✨ Normalize media type for layers during image rebasing

[mrozanc]

Fix for #2101

Ensure consistent media types (DockerLayer/OCILayer) across layers by adding logic to identify and normalize layer media types during the rebasing process. This prevents potential mismatches and ensures compatibility when constructing rebased images.

[google-cla]

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[mrozanc]

No idea what's going on with presubmit, but it looks like #908 problem. I'm using WSL to launch presubmit.

./hack/presubmit.sh logs

go: downloading honnef.co/go/tools v0.6.1
go: downloading golang.org/x/tools v0.30.0
go: downloading golang.org/x/exp/typeparams v0.0.0-20231108232855-2478ac86f678
go: downloading github.com/BurntSushi/toml v1.4.1-0.20240526193622-a339e1f7089c
go: downloading golang.org/x/exp v0.0.0-20231110203233-9a3e6036ecaa
go: downloading golang.org/x/sync v0.11.0
go: downloading golang.org/x/mod v0.23.0
/mnt/c/Users/marc/dev/golang/go-containerregistry
/mnt/c/Users/marc/dev/golang/go-containerregistry /mnt/c/Users/marc/dev/golang/go-containerregistry
ok      github.com/google/go-containerregistry/cmd/crane        3.230s
?       github.com/google/go-containerregistry/cmd/crane/cmd    [no test files]
?       github.com/google/go-containerregistry/cmd/crane/help   [no test files]
ok      github.com/google/go-containerregistry/cmd/gcrane       4.539s
?       github.com/google/go-containerregistry/cmd/gcrane/cmd   [no test files]
?       github.com/google/go-containerregistry/cmd/registry     [no test files]
ok      github.com/google/go-containerregistry/internal/and     (cached)
ok      github.com/google/go-containerregistry/internal/cmd     7.050s
ok      github.com/google/go-containerregistry/internal/compression     (cached)
?       github.com/google/go-containerregistry/internal/depcheck        [no test files]
?       github.com/google/go-containerregistry/internal/editor  [no test files]
ok      github.com/google/go-containerregistry/internal/estargz (cached)
ok      github.com/google/go-containerregistry/internal/gzip    (cached)
?       github.com/google/go-containerregistry/internal/httptest        [no test files]
?       github.com/google/go-containerregistry/internal/redact  [no test files]
ok      github.com/google/go-containerregistry/internal/retry   (cached)
?       github.com/google/go-containerregistry/internal/retry/wait      [no test files]
ok      github.com/google/go-containerregistry/internal/verify  (cached)
ok      github.com/google/go-containerregistry/internal/windows (cached)
ok      github.com/google/go-containerregistry/internal/zstd    (cached)
ok      github.com/google/go-containerregistry/pkg/authn        0.219s
ok      github.com/google/go-containerregistry/pkg/authn/github (cached)
?       github.com/google/go-containerregistry/pkg/compression  [no test files]
ok      github.com/google/go-containerregistry/pkg/crane        23.504s
ok      github.com/google/go-containerregistry/pkg/gcrane       9.197s
?       github.com/google/go-containerregistry/pkg/legacy       [no test files]
ok      github.com/google/go-containerregistry/pkg/legacy/tarball       (cached)
?       github.com/google/go-containerregistry/pkg/logs [no test files]
ok      github.com/google/go-containerregistry/pkg/name (cached)
ok      github.com/google/go-containerregistry/pkg/registry     2.140s
ok      github.com/google/go-containerregistry/pkg/v1   (cached)
ok      github.com/google/go-containerregistry/pkg/v1/cache     (cached)
ok      github.com/google/go-containerregistry/pkg/v1/compare   (cached)
ok      github.com/google/go-containerregistry/pkg/v1/daemon    (cached)
ok      github.com/google/go-containerregistry/pkg/v1/empty     (cached)
?       github.com/google/go-containerregistry/pkg/v1/fake      [no test files]
--- FAIL: TestGcloudErrors (0.62s)
    --- FAIL: TestGcloudErrors/error (0.24s)
        auth_test.go:119: wanted error, got nil
    --- FAIL: TestGcloudErrors/badoutput (0.19s)
        auth_test.go:119: wanted error, got nil
    --- FAIL: TestGcloudErrors/badexpiry (0.19s)
        auth_test.go:119: wanted error, got nil
--- FAIL: TestGcloudSuccess (0.24s)
    auth_test.go:146: wanted token "mytoken", got ""
--- FAIL: TestKeychainGCRandAR (1.82s)
    --- FAIL: TestKeychainGCRandAR/cases[0] (0.22s)
        auth_test.go:212: expected not anonymous auth for {gcr.io true}, got: &{}
        auth_test.go:223: expected not anonymous auth for {gcr.io true}, got: &{}
    --- FAIL: TestKeychainGCRandAR/cases[1] (0.17s)
        auth_test.go:212: expected not anonymous auth for {us.gcr.io true}, got: &{}
        auth_test.go:223: expected not anonymous auth for {us.gcr.io true}, got: &{}
    --- FAIL: TestKeychainGCRandAR/cases[2] (0.18s)
        auth_test.go:212: expected not anonymous auth for {eu.gcr.io true}, got: &{}
        auth_test.go:223: expected not anonymous auth for {eu.gcr.io true}, got: &{}
    --- FAIL: TestKeychainGCRandAR/cases[3] (0.18s)
        auth_test.go:212: expected not anonymous auth for {asia.gcr.io true}, got: &{}
        auth_test.go:223: expected not anonymous auth for {asia.gcr.io true}, got: &{}
    --- FAIL: TestKeychainGCRandAR/cases[4] (0.21s)
        auth_test.go:212: expected not anonymous auth for {staging-k8s.gcr.io true}, got: &{}
        auth_test.go:223: expected not anonymous auth for {staging-k8s.gcr.io true}, got: &{}
    --- FAIL: TestKeychainGCRandAR/cases[5] (0.13s)
        auth_test.go:212: expected not anonymous auth for {global.gcr.io true}, got: &{}
        auth_test.go:223: expected not anonymous auth for {global.gcr.io true}, got: &{}
    --- FAIL: TestKeychainGCRandAR/cases[9] (0.13s)
        auth_test.go:212: expected not anonymous auth for {us-docker.pkg.dev true}, got: &{}
        auth_test.go:223: expected not anonymous auth for {us-docker.pkg.dev true}, got: &{}
    --- FAIL: TestKeychainGCRandAR/cases[10] (0.14s)
        auth_test.go:212: expected not anonymous auth for {asia-docker.pkg.dev true}, got: &{}
        auth_test.go:223: expected not anonymous auth for {asia-docker.pkg.dev true}, got: &{}
    --- FAIL: TestKeychainGCRandAR/cases[11] (0.20s)
        auth_test.go:212: expected not anonymous auth for {europe-docker.pkg.dev true}, got: &{}
        auth_test.go:223: expected not anonymous auth for {europe-docker.pkg.dev true}, got: &{}
    --- FAIL: TestKeychainGCRandAR/cases[12] (0.26s)
        auth_test.go:212: expected not anonymous auth for {us-central1-docker.pkg.dev true}, got: &{}
        auth_test.go:223: expected not anonymous auth for {us-central1-docker.pkg.dev true}, got: &{}
FAIL
FAIL    github.com/google/go-containerregistry/pkg/v1/google    5.348s
ok      github.com/google/go-containerregistry/pkg/v1/layout    (cached)
ok      github.com/google/go-containerregistry/pkg/v1/match     (cached)
ok      github.com/google/go-containerregistry/pkg/v1/mutate    (cached)
ok      github.com/google/go-containerregistry/pkg/v1/partial   (cached)
ok      github.com/google/go-containerregistry/pkg/v1/random    (cached)
ok      github.com/google/go-containerregistry/pkg/v1/remote    5.496s
ok      github.com/google/go-containerregistry/pkg/v1/remote/transport  (cached)
ok      github.com/google/go-containerregistry/pkg/v1/static    (cached)
ok      github.com/google/go-containerregistry/pkg/v1/stream    (cached)
ok      github.com/google/go-containerregistry/pkg/v1/tarball   (cached)
ok      github.com/google/go-containerregistry/pkg/v1/types     (cached)
?       github.com/google/go-containerregistry/pkg/v1/validate  [no test files]
FAIL

Edit: actually it fails because when gcloud is not installed, the production code still looks for it and fallbacks to anonymous mode instead of using the mock provided in the test.