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
Test: lunch
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:406d7ae8afcea82f227278b2c20198ce94b143ca)
Merged-In: Iba97af30d474696210b68f5b35604bf04b953896
Change-Id: Iba97af30d474696210b68f5b35604bf04b953896
1 file changed