bgdexopt: fix deadlock between dump and dexopt thread

- Calling JobScheduler API under mLock leads into accessing
  PMS lock which is held when dump is called from PMS.
  : This leads into deadlock.
- Call JobScheduler outside mLock as that is safe without
  mLock.

Bug: 213945104
Test: run bgdexopt CTS which runs dump and dexopt thread.
Change-Id: I3aabd18e6ec1ec7e158eb008b90dee90b8621c60