Add launch assistant method.

Test: manual atest

Local test with atest on cf_x86_64_phone: 100/100 PASS.
ABTD 100/100 PASS: https://android-build.googleplex.com/builds/abtd/run/L71100000956341271

Change-Id: Ib9276d1cc395f134d77ba0237d94f4f23a3485b3
1 file changed