Fix e2e kokoro tests

[Tulsishah]

Description

Issue:
Kokoro tests on the release branch were failing due to Git's inability to identify the intended branch.

Error Message:

fatal: ambiguous argument 'read_cache_release': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]

Cause:
Missing remote branch information.

Resolution:
Resolved by explicitly specifying the remote branch using origin/$BRANCH_NAME.

Link to the issue in case of a bug fix.

NA

Testing details

1. Manual - Tested on local VM and kokoro
2. Unit tests - NA
3. Integration tests - NA