Add popUpCurrent to navController

Default false, if set to true, when navigate is call, current page will
be popped up from the back stack, so when back from the new page, will
not back to current one.

Also add unit tests.

Bug: 236346018
Test: Unit test
Test: Manually with Gallery
Change-Id: I5f8bb3fc20a8c38d1eecdbabd781df4581c165ba