Revert of [Reland] Upgrade to new Android SDK.

docs/android_test_instructions.md

 # Android Test Instructions
 
 [TOC]
 
 ## Device Setup
 
 ### Physical Device Setup
 
 #### ADB Debugging
 
@@ skipping 134 matching lines @@
 builder.
 
 ### INSTALL\_FAILED\_CONTAINER\_ERROR or INSTALL\_FAILED\_INSUFFICIENT\_STORAGE
 
 If you see this error when the test runner is attempting to deploy the test
 binaries to the AVD emulator, you may need to resize your userdata partition
 with the following commands:
 
 ```shell
 # Resize userdata partition to be 1G
-resize2fs android_emulator_sdk/sdk/system-images/android-24/x86/userdata.img 1G
+resize2fs android_emulator_sdk/sdk/system-images/android-23/x86/userdata.img 1G
 
 # Set filesystem parameter to continue on errors; Android doesn't like some
 # things e2fsprogs does.
-tune2fs -e continue android_emulator_sdk/sdk/system-images/android-24/x86/userdata.img
+tune2fs -e continue android_emulator_sdk/sdk/system-images/android-23/x86/userdata.img
 ```
 
 ## Symbolizing Crashes
 
 Crash stacks are logged and can be viewed using adb logcat. To symbolize the
 traces, define `CHROMIUM_OUTPUT_DIR=$OUTDIR` where `$OUTDIR` is the argument you
 pass to `ninja -C`, and pipe the output through
 `third_party/android_platform/development/scripts/stack`. If
 `$CHROMIUM_OUTPUT_DIR` is unset, the script will search `out/Debug` and
 `out/Release`. For example:
@@ skipping 131 matching lines @@
 See
 https://sites.google.com/a/chromium.org/dev/developers/testing/webkit-layout-tests
 
 ## Running GPU tests
 
 (e.g. the "Android Debug (Nexus 7)" bot on the chromium.gpu waterfall)
 
 See http://www.chromium.org/developers/testing/gpu-testing for details. Use
 `--browser=android-content-shell`. Examine the stdio from the test invocation on
 the bots to see arguments to pass to `src/content/test/gpu/run_gpu_test.py`.