Fix NPE on a device having no sensor

If a device has no sensor, mUidPolicy isn't set. So mUidPolicy should be
initialized unconditionally.

Bug: 77151317
Bug: 76407833
Test: succeeded building and tested with a device having no sensor
Change-Id: I3ef9f252c220d58bdab5e4f458e48b74b66091ee
1 file changed