[Android] Add timeout_scale for Lollipop Low-end Tester.

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 1370 matching lines @@
       },
       {
         "test": "ui_touch_selection_unittests"
       },
       {
         "test": "unit_tests"
       }
     ],
     "instrumentation_tests": [
       {
-        "test": "android_webview_test_apk"
+        "test": "android_webview_test_apk",
+        "timeout_scale": 2
       },
       {
-        "apk_under_test": "Blimp.apk",
         "override_compile_targets": [
           "blimp_test_apk"
         ],
         "test": "blimp_test_apk",
-        "test_apk": "BlimpTest.apk"
+        "timeout_scale": 2
       },
       {
-        "test": "chrome_public_test_apk"
+        "test": "chrome_public_test_apk",
+        "timeout_scale": 2
       },
       {
-        "test": "chrome_sync_shell_test_apk"
+        "test": "chrome_sync_shell_test_apk",
+        "timeout_scale": 2
       },
       {
-        "test": "content_shell_test_apk"
+        "test": "content_shell_test_apk",
+        "timeout_scale": 2
       }
     ]
   },
   "Lollipop Phone Tester": {
     "gtest_tests": [
       {
         "test": "android_webview_unittests"
       },
       {
         "test": "base_unittests"
@@ skipping 418 matching lines @@
       },
       {
         "test": "chrome_sync_shell_test_apk"
       },
       {
         "test": "content_shell_test_apk"
       }
     ]
   }
 }