[WebView] Fix perf builders no longer building WebView apks.

scripts/slave/recipes/android/builder.expected/full_chromium_perf_Android_Builder.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[depot_tools::bot_update]/resources/bot_update.py",
       "--master",
       "chromium.perf",
       "--builder",
       "Android Builder",
@@ skipping 166 matching lines @@
       "--compiler",
       "goma",
       "--goma-jsonstatus",
       "/path/to/tmp/json",
       "--goma-dir",
       "[BUILD]/goma",
       "--",
       "android_tools",
       "cc_perftests",
       "chrome_public_apk",
-      "gpu_perftests"
+      "gpu_perftests",
+      "system_webview_apk",
+      "system_webview_shell_apk"
     ],
     "cwd": "[SLAVE_BUILD]",
     "env": {
       "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
     },
     "name": "compile",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output (invalid)@null@@@",
       "@@@STEP_LOG_END@json.output (invalid)@@@"
     ]
@@ skipping 30 matching lines @@
     "~followup_annotations": [
       "@@@STEP_LINK@gsutil.upload@https://storage.cloud.google.com/chrome-perf/android_perf_rel/full-build-linux_267739.zip@@@"
     ]
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]