Update README.md

Updated custom runner args doc with new android.testInstrumentationRunnerArguments.x namespace

Author: slinzner

AndroidTestingBlueprint/README.md

@@ -181,7 +181,7 @@ Since Gradle Android Plugin version 1.2.0 using ProGuard has become a lot easier
 To try it out just uncomment the minify section for the debug build type in the app modules `build.gradle` file.
 
 ## Custom Gradle command-line arguments
-Gradle allows you to pass custom arguments to `AndroidJUnitRunner`. This is equivalent to running `adb shell am instrument -w -e <argName> <argValue>`.
+Gradle allows you to pass custom arguments to `AndroidJUnitRunner`. This is equivalent to running `adb shell am instrument -w -e <argName> <argValue> com.example.android.testing.blueprint.test/android.support.test.runner.AndroidJUnitRunner`.
 Custom arguments can be particularly useful when you just want to run a specific test class/method/qualifier.
 
 To pass a custom argument the -Pcom.android.tools.instrumentationTestRunnerArgs=argName=argValue
@@ -190,19 +190,19 @@ property needs to be used, in conjunction with `argName` and `argValue`. Multipl
 For instance, to run all tests annotated with the `@Large` test size qualifier in the app module, execute:
 
 ``` sh
-`./gradlew app:connectedCheck -Pcom.android.tools.instrumentationTestRunnerArgs=size=large`
+./gradlew app:connectedCheck -Pandroid.testInstrumentationRunnerArguments.size=large
 ```
 
 To only run tests for a specific test class, i.e. EspressoTest, execute:
 
 ``` sh
-`./gradlew app:connectedCheck -Pcom.android.tools.instrumentationTestRunnerArgs=class=com.example.android.testing.blueprint.ui.espresso.EspressoTest`
+./gradlew app:connectedCheck -Pandroid.testInstrumentationRunnerArguments.class=com.example.android.testing.blueprint.ui.espresso.EspressoTest
 ```
 
 To pass in an arbitrary argument which can be accessed in a test at runtime, execute:
 
 ``` sh
-`./gradlew module-flavor1-androidTest-only:connectedCheck -Pcom.android.tools.instrumentationTestRunnerArgs=argument1=make_test_fail`
+`./gradlew module-flavor1-androidTest-only:connectedCheck -Pandroid.testInstrumentationRunnerArguments.argument1=make_test_fail`
 ```
 All arguments passed through command line can also be specified in the project's build.gradle file, which is
 great for specifying values which are required by the test harness itself. The `argument1` from the previous