Read Aloud: fix browser controls position issues after theme change

If the theme is changed during playback, the player UI is recreated
while the main activity isn't visible the settings activity is on
screen instead.
 * The top toolbar control container height is 0, so when called back
   with browser controls offset changes, getToolbarExtraYOffset()
   gives the wrong result, placing the toolbar too low.
 * The bottom controls need to be translated to match the bottom
   controls min height whenever the real view becomes visible, not
   just at the end of min height animations.
 * Plumb the Read Aloud mini player show status over to
   BottomControlsMediator to help with positioning the bottom controls
   after restore when the usual height change animation callback won't
   be called.

Bug: 329823963
Change-Id: I2a08fe96fc4f80fe9583bd2ef9aeddb9e32c9ab7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5384105


Reviewed-by: Matthew Jones <mdjones@chromium.org>
Reviewed-by: Basia Zimirska <basiaz@google.com>
Commit-Queue: Ian Wells <iwells@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1279967}