Add breakpad support to mojo shell apk.

shell/crash/BUILD.gn

+# Copyright 2015 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.
+
+if (is_android) {
+  import("//build/config/android/config.gni")
+}
+
+source_set("crash") {
+  sources = [
+    "breakpad.cc",
+    "breakpad.h",
+  ]
+
+  if (is_android) {
+    libs = [ "log" ]
+  }
+
+  deps = [
+    "//base",
+    "//third_party/breakpad:client",
+  ]
+}