Revert the window context creation in NavigationBarController

In ag/14981905, we changed it to use WindowContext of
TYPE_NAVIGATION_BAR, but looks like this context is also used for
creating windows of other types.

Revert it to fix the crash. Will fix the context usages in NavigationBar
later.

Bug: 193107004
Test: revert
Change-Id: I4ec66982aa929039764fc276e9452151d959268e