AAPT2: Add a daemon mode

Gradle and other build tools that need to frequently interact with aapt2
can use the daemon mode to issue regular CLI commands without paying
the process start cost for each invocation.

Test: manual
Bug: 65645766
Change-Id: I543858ed46496278bad643f0dae688c924ec6c3f
Merged-In: I543858ed46496278bad643f0dae688c924ec6c3f
3 files changed