[Android] Default to test name as compile target for instrumentation tests.

scripts/slave/recipes/chromium.expected/dynamic_instrumentation_nodefault_test.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[depot_tools::bot_update]/resources/bot_update.py",
       "--master",
       "chromium.linux",
       "--builder",
       "Android Tests",
@@ skipping 207 matching lines @@
       "[SLAVE_BUILD]/src/testing/buildbot/chromium.linux.json",
       "/path/to/tmp/json"
     ],
     "name": "read test spec",
     "~followup_annotations": [
       "@@@STEP_TEXT@path: [SLAVE_BUILD]/src/testing/buildbot/chromium.linux.json@@@",
       "@@@STEP_LOG_LINE@json.output@{@@@",
       "@@@STEP_LOG_LINE@json.output@  \"Android Tests\": {@@@",
       "@@@STEP_LOG_LINE@json.output@    \"instrumentation_tests\": [@@@",
       "@@@STEP_LOG_LINE@json.output@      {@@@",
-      "@@@STEP_LOG_LINE@json.output@        \"additional_apks\": [@@@",
-      "@@@STEP_LOG_LINE@json.output@          \"another_apk\", @@@",
-      "@@@STEP_LOG_LINE@json.output@          \"omg_so_many_apks\"@@@",
-      "@@@STEP_LOG_LINE@json.output@        ], @@@",
-      "@@@STEP_LOG_LINE@json.output@        \"apk_under_test\": \"second_apk\", @@@",
-      "@@@STEP_LOG_LINE@json.output@        \"test\": \"ChromePublicTest\", @@@",
-      "@@@STEP_LOG_LINE@json.output@        \"test_apk\": \"one_apk\"@@@",
+      "@@@STEP_LOG_LINE@json.output@        \"test\": \"blimp_test_apk\"@@@",
       "@@@STEP_LOG_LINE@json.output@      }@@@",
       "@@@STEP_LOG_LINE@json.output@    ]@@@",
       "@@@STEP_LOG_LINE@json.output@  }@@@",
       "@@@STEP_LOG_LINE@json.output@}@@@",
       "@@@STEP_LOG_END@json.output@@@"
     ]
   },
   {
     "cmd": [
       "python",
@@ skipping 303 matching lines @@
       "Android Tests",
       "--blacklist-file",
       "[SLAVE_BUILD]/src/out/bad_devices.json"
     ],
     "name": "spawn_device_monitor"
   },
   {
     "cmd": [
       "python",
       "-u",
-      "[SLAVE_BUILD]/src/out/Release/bin/run_chrome_public_test_apk",
+      "[SLAVE_BUILD]/src/out/Release/bin/run_blimp_test_apk",
       "--blacklist-file",
       "[SLAVE_BUILD]/src/out/bad_devices.json",
       "--verbose",
       "--json-results-file",
       "/path/to/tmp/json"
     ],
-    "name": "Instrumentation test ChromePublicTest",
+    "name": "Instrumentation test blimp_test_apk",
     "~followup_annotations": [
       "step returned non-zero exit code: 1",
       "@@@STEP_TEXT@<br/>failures:<br/>Test.Two<br/>@@@",
       "@@@STEP_FAILURE@@@"
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[build::test_results]/resources/upload_gtest_test_results.py",
       "--input-gtest-json",
       "{\"per_iteration_data\": [{\"Test.One\": [{\"elapsed_time_ms\": 0, \"output_snippet\": \"\", \"status\": \"SUCCESS\"}], \"Test.Three\": [{\"elapsed_time_ms\": 0, \"output_snippet\": \"\", \"status\": \"SUCCESS\"}], \"Test.Two\": [{\"elapsed_time_ms\": 0, \"output_snippet\": \"\", \"status\": \"FAILURE\"}]}]}",
       "--master-name",
       "chromium.linux",
       "--builder-name",
       "Android Tests",
       "--build-number",
       "571",
       "--test-type",
-      "ChromePublicTest",
+      "blimp_test_apk",
       "--test-results-server",
       "test-results.appspot.com",
       "--chrome-revision",
       "refs/heads/master@{#170242}"
     ],
-    "name": "Upload to test-results [ChromePublicTest]"
+    "name": "Upload to test-results [blimp_test_apk]"
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE_REPO[build]/scripts/slave/daemonizer.py",
       "--action",
       "stop",
       "--pid-file-path",
       "/tmp/device_monitor.pid"
@@ skipping 75 matching lines @@
       "@@@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@@@"
     ]
   },
   {
     "name": "$result",
-    "reason": "1 tests failed: ['ChromePublicTest']",
+    "reason": "1 tests failed: ['blimp_test_apk']",
     "status_code": 1
   }
 ]