Bump timeout for chrome_public_test_apk.

testing/buildbot/chromium.android.json

 {
   "Android GN Builder (dbg)": {
     "additional_compile_targets": [
       "blimp_tests",
       "chrome_public_apk",
       "chrome_public_test_apk",
       "content_shell_apk",
       "content_shell_test_apk",
       "system_webview_apk"
     ]
@@ skipping 105 matching lines @@
         ],
         "override_isolate_target": "chrome_public_test_apk",
         "swarming": {
           "can_use_on_swarming_builders": true,
           "dimension_sets": [
             {
               "device_os": "MMB29Q",
               "device_type": "bullhead"
             }
           ],
-          "hard_timeout": 2400
+          "hard_timeout": 3600
         },
         "test": "chrome_public_test_apk"
       },
       {
         "override_compile_targets": [
           "chrome_sync_shell_test_apk"
         ],
         "override_isolate_target": "chrome_sync_shell_test_apk",
         "swarming": {
           "can_use_on_swarming_builders": true,
@@ skipping 1700 matching lines @@
       },
       {
         "test": "chrome_sync_shell_test_apk"
       },
       {
         "test": "content_shell_test_apk"
       }
     ]
   }
 }