Separate out FalsingManager#isFalseTap

Method no longer takes `robustCheck` parameter. Instead,
FalsingManager#isSimpleTap is added for basic checking, and
FalsingManager#isTap does robust checking by default.

FalsingManager#isTap takes an enum value for penalty instead of
a double, making the value more understandable.

Bug: 172655679
Test: atest SystemUITests && manual
Change-Id: Ib4a99f87bcd6acee67a98420f460c98d44fa6360