Use debug apks for dev builds.

shell/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/ui.gni")
 import("//mojo/public/mojo.gni")
 import("//mojo/public/mojo_application.gni")
 import("//mojo/public/tools/bindings/mojom.gni")
 import("//mojo/tools/embed/rules.gni")
 import("//testing/test.gni")
@@ skipping 431 matching lines @@
     ]
     deps = [
       "//services/test_service:test_app",
       "//services/test_service:test_request_tracker_app",
     ]
   }
 
   if (!is_official_build) {
     manifest_package = "org.chromium.mojo.shell"
     apk_name = "Mojo Shell (dev)"
+    debuggable = "true"
   } else {
     manifest_package = "io.mojoapps.launcher"
     apk_name = "Mojo Shell"
+    debuggable = "false"
   }
 
   if (is_official_build) {
     # Force GN to re-generate ninja files when a new commit is present.
     read_file("//.git/index", "")
     version_code =
         exec_script("//mojo/public/tools/gn/last_commit_timestamp.py",
                     [
                       "--directory",
                       rebase_path("//", root_build_dir),
@@ skipping 16 matching lines @@
                                     [ "keystore_password" ],
                                     "trim string")
   } else {
     version_code = "1"
   }
   version_name = "0.0.1"
 
   jinja_variables = [
     "manifest_package=$manifest_package",
     "apk_name=$apk_name",
+    "debuggable=$debuggable",
     "version_code=$version_code",
     "version_name=$version_name",
   ]
 
   mojo_shell_manifest =
       "$target_gen_dir/mojo_shell_manifest/AndroidManifest.xml"
 
   jinja_template("mojo_shell_manifest") {
     variables = jinja_variables
     input = "android/apk/AndroidManifest.xml.jinja2"
@@ skipping 196 matching lines @@
       "${root_out_dir}/libmojo_shell.so",
     ]
   } else {
     sources += [ "${root_out_dir}/mojo_shell" ]
   }
 
   outputs = [
     "${root_out_dir}/symbols/{{source_file_part}}",
   ]
 }