Make it so that the grant dialog's position can be changed

The vertical position of a floating window is unable to be
changed so now we have the window occupy the entire screen
and add a new layout inside the scrollview so that position
can be set.

Doing this made animations for the dialog vanish, probably
because the root is now transparent. So animations had to
be added for the dialog.

This also fixes the weird behavior where scrolling the dialog
was inside the bounds of the rounded rectangle. Now the whole
dialog moves as a single rectangle and can scroll off screen.

Bug: 120435328
Test: atest CtsAppSecurityHostTestCases:android.appsecurity.cts.PermissionsHostTest
      Looked at dark theme, various display sizes, font sizes,
          landscape, portrait. All cases looked the same as before

Change-Id: I1d85d89711f9e5404d2eeeb60f77d77c5eb01340