recipes-graphics/wayland/agl-compositor_git: Bump agl-compositor SRCVREV

recipes-graphics/wayland/agl-compositor_git: Bump agl-compositor SRCVREV

The most notable change is an update in the agl-shell protocol and with
a version increase. A few other bug-fixes have also made it.

Specifically, since the previous update the following changes have
added:

- 471a12ee38098aaa agl-compositor:Add NULL check after zalloc in src directory
- 18918978ba5c0f91 agl-compositor:Add NULL check after zalloc in screenshooter.c
- 6371b14eb0abbb23 agl-compositor: Correct several spell issues in the protocol xml files
- 53046f8863e0320d agl-compositor: Correct several spell or grammar issues in the README.md file.
- fd4708c898aafc58 layout: Remove explicit damage call
- d456a0c59a316f8f layout: Inflict damage on all subsurfaces
- c0bc469e505b91e0 meson.build: Bump compositor version
- 9e9c768ad6360ef5 shell: Refactor pending surfaces for existing pending ones
- 6d4038380b39f204 src/desktop: Add a compositor destroy listener
- 5101851ecb304e75 src/shell: Add set_app_property_mode request
- e4f4aef1a5b1feb9 layout: Fix-up the positions when placing the pop-up/dialog
- 52df92d73985dba8 shell: Fix passing maximized state from the start
- b25020f9a5055c4c meson.build: Add a waltham-transmitter pkg-config pc file
- e5016cbc47b46b86 meson.build: Conditionally build with headless support
- d6f64b665a39e0bd meson.build: Clarify out-of-tree build error
- 5b8d4c56e7d793cf clients/screenshooter: Fix taking screenshot on multiple outputs

Note that with this bump update, starting with `c0bc469e505b91e0
meson.build: Bump compositor version` all clients using the agl-shell
protocol will have to be updated to use agl-compositor-protocols-0.0.20
version.

Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
Change-Id: Ica7bb61f16664fb74f051fd7bf2e61120cb1dba7
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/c/AGL/meta-agl/+/27074
ci-image-build: Jenkins Job builder account
Tested-by: Jenkins Job builder account
ci-image-boot-test: Jenkins Job builder account
Reviewed-by: Scott Murray <scott.murray@konsulko.com>
Reviewed-by: Jan-Simon Moeller <jsmoeller@linuxfoundation.org>