hwc: external: Add screen-fitting to external panel.

Screen fitting for out-of-bounds videos (with overlays) exists for primary
panel. Add this same support for external panels, so that GPU won't be needed
in panning use-cases.

Bug: 7313955
Change-Id: I274a821264d87098227b144752f4d0b89d342cd9
Signed-off-by: Iliyan Malchev <malchev@google.com>
2 files changed