Add metadata to config_gen

If an AndroidTest.xml exists and contains plan name, the plan is written
to the generated config. Otherwise, the plan is "vts-staging-fuzz".

Bug: 70485967
Test: python update_makefiles.py --config
Change-Id: Ia79589543f9ba817fef67a3d30d2a6a55d1983c3
2 files changed