make it possible to disable debug symbols stripping (flutter/engine#11265)

engine/src/flutter/shell/config.gni

@@ -5,4 +5,5 @@
 declare_args() {
   shell_enable_vulkan = false
   shell_enable_metal = false
+  stripped_symbols = true
 }

engine/src/flutter/shell/platform/android/BUILD.gn

@@ -306,9 +306,15 @@ action("icudtl_object") {
 action("android") {
   script = "//build/android/gyp/create_flutter_jar.py"
 
+  if (stripped_symbols) {
+    engine_library = "lib.stripped/libflutter.so"
+  } else {
+    engine_library = "libflutter.so"
+  }
+
   inputs = [
     "$root_build_dir/$embedding_jar_filename",
-    "$root_build_dir/lib.stripped/libflutter.so",
+    "$root_build_dir/$engine_library",
   ]
 
   engine_artifact_id =
@@ -329,7 +335,7 @@ action("android") {
     "--dist_jar",
     rebase_path(embedding_jar_filename, root_build_dir, root_build_dir),
     "--native_lib",
-    rebase_path("lib.stripped/libflutter.so", root_build_dir, root_build_dir),
+    rebase_path("$engine_library", root_build_dir, root_build_dir),
     "--android_abi",
     "$android_app_abi",
   ]

engine/src/flutter/tools/gn

@@ -264,6 +264,8 @@ def to_gn_args(args):
       if args.build_glfw_shell:
         gn_args['build_glfw_shell'] = True
 
+    gn_args['stripped_symbols'] = args.stripped
+
     return gn_args
 
 def parse_args(args):
@@ -335,6 +337,10 @@ def parse_args(args):
   parser.add_argument('--bitcode', default=False, action='store_true',
                       help='Enable bitcode for iOS targets. On debug runtime modes, this will be a marker only.')
 
+  parser.add_argument('--stripped', default=True, action='store_true',
+                      help='Strip debug symbols from the output. This defaults to true and has no effect on iOS.')
+  parser.add_argument('--no-stripped', dest='stripped', action='store_false')
+
   return parser.parse_args(args)
 
 def main(argv):