Add frameworks-base-overlays to GSI target

Currently the GSI targets are missing the navigation mode overlays,
which are required to switch between three button and gesture navigation
modes. This adds the missing packages through the
frameworks-base-overlays defintion, to maintain consistency with the
base targets.

Flag: EXEMPT bugfix
Bug: 384552117
Test: flash GSI and verify OverlayManagerService state
  atest InputMethodServiceTest#testOnCustomImeSwitcherButtonRequestedVisible_gestureNav
  InputMethodServiceTest#testOnCustomImeSwitcherButtonRequestedVisible_threeButtonNav
Change-Id: I3b604efe5da1c66e031adc5614fa5bcccdd655b7