Forward launch_cvd flags to assemble_cvd and run_cvd.

This adds generic flag forwarding for subprocesses. It runs
subprocesses with "--helpxml" to dynamically find the flag definitions,
then registers these as if they were locally defined flags. It then
forwards the relevant flags to subprocesses when they are invoked.

Test: "launch_cvd --help", "launch_cvd --daemon"
Bug: 269465138
Change-Id: Icbfe366b2e6d4cf75ad84b1563a26eecd8ec5981
6 files changed
tree: 74484dfd1f15deff31042d77337ae6b7cdccd80d
  1. common/
  2. guest/
  3. host/
  4. tests/
  5. tools/
  6. Android.bp
  7. Android.mk
  8. OWNERS
  9. TEST_MAPPING