Implement Timer for one handed to handle auto-exit (8/N)

1) The timeout values defined in Settings
2) When user dragging in displayArea reset timer
3) When stop one handed remove timer

Test: atest OneHandedDisplayAreaOrganizerTest
Test: atest OneHandedManagerImplTest
Test: atest OneHandedUITest
Test: atest OneHandedSettingsUtilTest
Test: atest SystemUITests
Test: atest DisplayAreaPolicyBuilderTest
Bug: 150747909
Change-Id: I10ff6e574cd806dfab69f64732017e90c4a8d0e4