Fix issue that widget drag and drop failed when are off

Remove extra screen & go to normal state only if widget
addition was complete. If a config activity was started, then
don't change to remove screen yet or go to normal state. Else,
QuickStepLauncher clears the existing activity open requests when
going to normal state. When animations are off, this led to config activity to never launch and hence, such widgets not being added.

Bug: 369422714
Test: Manual
Flag: EXEMPT BUGFIX
Change-Id: I4e7e29fd998a0cc5ca18a7a48b91a5b788a60a52