ci/debian-android: move pkgconfig paths to the cross file

Move pkgconfig paths out of the job script into the cross file.
Use pkg_config_libdir on the cross file instead.
Which makes more sense and cleaner code.

Suggested-by: David Heidelberg <david.heidelberg@collabora.com>
Suggested-by: Roman Stratiienko <r.stratiienko@gmail.com>
Signed-off-by: Helen Koike <helen.koike@collabora.com>
Reviewed-by: Sergi Blanch Torné <sergi.blanch.torne@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20019>

.gitlab-ci/container/create-android-cross-file.sh

@@ -31,5 +31,6 @@ endian = 'little'
 
 [properties]
 needs_exe_wrapper = true
+pkg_config_libdir = '/usr/local/lib/${arch2}/pkgconfig/:/${ndk}/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/lib/${arch2}/pkgconfig/'
 
 EOF