WebRTC: Rename trybots and add compile-only configs.

scripts/slave/recipes/webrtc/standalone.expected/tryserver_webrtc_android_dbg.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "[BUILD]/scripts/slave/bot_update.py",
       "--master",
       "tryserver.webrtc",
       "--builder",
-      "android",
+      "android_dbg",
       "--slave",
       "slavename",
       "--spec",
       "cache_dir = None\nsolutions = [{'deps_file': 'DEPS', 'managed': True, 'name': 'src', 'url': 'https://chromium.googlesource.com/external/webrtc'}, {'deps_file': 'DEPS', 'managed': True, 'name': 'webrtc-limited', 'url': 'https://chrome-internal.googlesource.com/chrome/deps/webrtc-limited'}]\ntarget_os = ['android']",
       "--root",
       "src",
       "--revision_mapping_file",
       "{\"src\": \"got_revision\"}",
       "--issue",
       "666666",
@@ skipping 220 matching lines @@
       "[BUILD]/scripts/slave/daemonizer.py",
       "--action",
       "restart",
       "--pid-file-path",
       "/tmp/device_monitor.pid",
       "--",
       "RECIPE_MODULE[chromium_android]/resources/spawn_device_temp_monitor.py",
       "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools/adb",
       "[\"07a00ca4\"]",
       "tryserver.webrtc",
-      "android"
+      "android_dbg"
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "spawn_device_temp_monitor"
   },
   {
     "cmd": [
       "python",
       "-u",
       "[SLAVE_BUILD]/src/webrtc/build/android/test_runner.py",
       "gtest",
@@ skipping 286 matching lines @@
       "@@@STEP_LOG_LINE@python.inline@import glob, os, sys@@@",
       "@@@STEP_LOG_LINE@python.inline@for report in glob.glob(sys.argv[1]):@@@",
       "@@@STEP_LOG_LINE@python.inline@  with open(report, 'r') as f:@@@",
       "@@@STEP_LOG_LINE@python.inline@    for l in f.readlines():@@@",
       "@@@STEP_LOG_LINE@python.inline@      print l@@@",
       "@@@STEP_LOG_LINE@python.inline@  os.remove(report)@@@",
       "@@@STEP_LOG_END@python.inline@@@"
     ]
   }
 ]