Ignore ACTION_OUTSIDE in FalsingManager

Multipe outside motion events can be fired for a single tap. This
throws off the falsing manager, causing it to improperly increase
its belief in false touches. Ignore them.

A few other small cleanups in the interaction between the
WalletActivity and the FalsingManager are also included. There was
one touch interaction with the wallet carousel that was not being
analyzed by the FalsingManager. The WalletActivity was also making
some redundant checks that the FalsingManager is already performaing
internally.

Fixes: 215558965
Test: manual & atest SystemUITests
Change-Id: I51139fdaaa0214b7a9ddfb9b730a1c8b114c721d