meson: turn android-libbacktrace into a feature option

Signed-off-by: Eric Engestrom <eric@igalia.com>
Reviewed-by: Dylan Baker <dylan@pnwbakers.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20915>

.gitlab-ci/build/gitlab-ci.yml

@@ -345,7 +345,7 @@ debian-android:
       -D llvm=disabled
       -D platform-sdk-version=33
       -D valgrind=disabled
-      -D android-libbacktrace=false
+      -D android-libbacktrace=disabled
     GALLIUM_ST: >
       -D dri3=disabled
       -D gallium-vdpau=disabled

meson.build

@@ -818,14 +818,10 @@ if with_android_stub and not with_platform_android
   error('`-D android-stub=true` makes no sense without `-D platforms=android`')
 endif
 
-if get_option('android-libbacktrace') == 'auto'
-  with_libbacktrace = with_platform_android
-else
-  with_libbacktrace = get_option('android-libbacktrace') == 'true'
-  if with_libbacktrace and not with_platform_android
-    error('`-D android-libbacktrace=true` makes no sense without `-D platforms=android`')
-  endif
-endif
+with_libbacktrace = get_option('android-libbacktrace') \
+  .require(with_platform_android, error_message : '`-D android-libbacktrace=enabled` makes no sense without `-D platforms=android`') \
+  .disable_auto_if(not with_platform_android) \
+  .allowed()
 
 if with_libbacktrace
   cpp_args += '-DWITH_LIBBACKTRACE'

meson_options.txt

@@ -45,9 +45,7 @@ option(
 )
 option(
   'android-libbacktrace',
-  type : 'combo',
-  value : 'auto',
-  choices : ['auto', 'true', 'false'],
+  type : 'feature',
   description : 'Use Android\'s libbacktrace',
 )
 option(