Bug 1454671 - Combine default log and gecko.log in automation on Android. r=ato

To ease investigation of failures the gecko log should be streamed
to stdout so it will be part of the default log. It helps with
correlating tracing output with the appropriate test.

MozReview-Commit-ID: JnH64bhhtgk

--HG--
extra : rebase_source : b50707189c181a865ab66dac8b3cb4e258a8e427

testing/mozharness/configs/android/android_common.py

@@ -253,7 +253,7 @@ config = {
                 "--address=%(address)s",
                 "%(test_manifest)s",
                 "--disable-e10s",
-                "--gecko-log=%(gecko_log)s",
+                "--gecko-log=-",
                 "--log-raw=%(raw_log_file)s",
                 "--log-errorsummary=%(error_summary_file)s",
                 "--symbols-path=%(symbols_path)s",

testing/mozharness/scripts/android_emulator_unittest.py

@@ -441,7 +441,6 @@ class AndroidEmulatorTest(TestingMixin, EmulatorMixin, BaseScript, MozbaseMixin)
             'error_summary_file': error_summary_file,
             # marionette options
             'address': c.get('marionette_address'),
-            'gecko_log': os.path.join(dirs["abs_blob_upload_dir"], 'gecko.log'),
             'test_manifest': os.path.join(
                 dirs['abs_marionette_tests_dir'],
                 self.config.get('marionette_test_manifest', '')