Notify DexManager about new package installs

This will update the internal cache so that the secondary dex files of
the new package can be found when loaded.

Test: runtest -x .../DexManagerTests.java

Bug: 32871170

(cherry picked from commit 0d4b8f8b)

Change-Id: I34008f6d262f19e88a346a36b83e4093b4129105

Merged-In: I0cb7158af249feeb01cf578a7544dda978eede9d