Update meson to 0.63.0

Reason: meson 0.63.0 provides a new feature which allows user to apply
diff file on a subproject. This gives user a flexibility to have code
changes in subprojects while running the unit test.

Reference: https://mesonbuild.com/Wrap-dependency-system-manual.html#diff-files

Tested: Locally ran unit test and confirmed that the subproject applied
the diff files correctly.

Signed-off-by: Michael Shen <gpgpgp@google.com>
Change-Id: Icb1ad03d28496120f5afe8010cfa3a3b855975c8
1 file changed