[Android] Only pass --adb-path to adb_install_apk for M51 and above.

scripts/slave/recipe_modules/chromium_android/example.expected/downgrade_install_tester_basic.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "\nimport os, sys\n\nbuild_path = sys.argv[1]\nif os.path.exists(build_path):\n  for (path, dir, files) in os.walk(build_path):\n    for cur_file in files:\n      if cur_file.endswith('index.lock'):\n        path_to_file = os.path.join(path, cur_file)\n        print 'deleting %s' % path_to_file\n        os.remove(path_to_file)\n",
       "[SLAVE_BUILD]"
     ],
     "name": "cleanup index.lock",
     "~followup_annotations": [
@@ skipping 518 matching lines @@
       "1800"
     ],
     "env": {
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json",
       "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
     },
     "name": "provision_devices (2)"
   },
   {
     "cmd": [
+      "python",
+      "-u",
+      "\nimport shutil\nimport sys\nshutil.copy(sys.argv[1], sys.argv[2])\n",
+      "[SLAVE_BUILD]/src/chrome/VERSION",
+      "/path/to/tmp/"
+    ],
+    "name": "get version (2)"
+  },
+  {
+    "cmd": [
       "[SLAVE_BUILD]/src/build/android/adb_install_apk.py",
       "apk",
       "-v",
       "--blacklist-file",
       "[SLAVE_BUILD]/src/out/bad_devices.json",
       "--adb-path",
       "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools/adb",
       "--downgrade",
       "--release"
     ],
@@ skipping 151 matching lines @@
       "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
     },
     "name": "stack_tool_for_asan"
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]