Reset override config when clearSizeCompat

Without this fix, after display density change, clicking size compat
restart button won't relaunch the app in new density.

Fix: 214339093
Fix: 209389023
Test: atest WmTests:SizeCompatTests#testClearSizeCompat_resetOverrideConfig
Change-Id: I6db7a2c2250c17d735938acc84e39d883d466aa6