Switch from engine-gecko-nightly to engine-gecko-beta (GV 67 Beta)

[cpeterso]

Fenix MVP will ship GV 67, which just rode from the GV Nightly channel to Beta. Fenix Nightly builds should now use GV 67 Beta builds. @pocmo will need to update AC's engine-gecko-beta component to use GV 67 Beta. IIUC, Fenix should then get the right GV version by just switching to engine-gecko-beta.

When GV 67 rides from the Beta channel to Release (2019-05-14), Fenix will need to switch to a different engine-gecko version.

┆Issue is synchronized with this Jira Task

[pocmo]

Depends on mozilla-mobile/android-components#2374

[cpeterso]

Note that we want Fenix to use geckoview-beta-armeabi-v7a, NOT geckoview-beta-arm64-v8a. GV 68 Nightly includes the new ARM64 Ion JIT, but GV 67 Beta does not.

[pocmo]

@cpeterso You mean we do not want to ship a Fenix ARM64 build?

[cpeterso]

Correct. At this time, we do not want to ship ARM64 builds of GV 67. Will users with Fenix ARM64 builds get updated or stuck when a new Fenix ARMv7 update is available with a greater version number?

[pocmo]

They should get updated to the ARMv7 build.

[cpeterso]

@pocmo - This issue suggesting Fenix switch from engine-gecko-nightly to engine-gecko-beta (GV 67 Beta) is still open, but I just confirmed that Fenix Nightly is using GV 67. Fenix is still using a very old version of GV 67 Nightly from 2019-03-18 (build 67.0-20190318154932).

FWIW, we now want Fenix Nightly to use GV 68 Nightly, so we want to WONTFIX this issue. I will file a new bug about switching from GV 67 to GV 68 Nightly.