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:f4d66514e8e6c05b2fe53d0f0c97eae5da0688d3)
Merged-In: I293119e6bb0e62d12b890899e7aa02dc12de7619
Change-Id: I293119e6bb0e62d12b890899e7aa02dc12de7619
1 file changed