Fix lunch choices for git_main

We add "trunk_staging-" for all COMMON_LUNCH_CHOICES so they are
valid in the trunk stable setup.

Bug: 307738446
Bug: 317213158
Test: lunch
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:748a543cf5b95a759cb9525388ad310c1108bd8a)
Merged-In: I397a8e2cbbca7979a4c4f122df0cc84d7f84bd4b
Change-Id: I397a8e2cbbca7979a4c4f122df0cc84d7f84bd4b
1 file changed