TouchHandler to handle touch events inside & outside displayArea (9/N)

1) Monitor the region out of displayArea when start one handed
2) When user is operating in displayArea, reset timer

Test: atest OneHandedDisplayAreaOrganizerTest
Test: atest OneHandedManagerImplTest
Test: atest OneHandedUITest
Test: atest OneHandedSettingsUtilTest
Test: atest SystemUITests
Test: atest DisplayAreaPolicyBuilderTest
Bug: 150747909
Change-Id: I60265fc8547a23a010c692d11ae63a2101102706