Convert tests to consistent structure

Use JUnit4 runner (from Espresso core jar), @Before annotation
for initial setup, @Test for all test methods. Move away from
the deprecated ActivityInstrumentationTestCase2 base class.

Bug: 27155526

Change-Id: I537fd4322c494597e80ecf8c9bd73b7f82fe8271
diff --git a/v7/gridlayout/build.gradle b/v7/gridlayout/build.gradle
index 6e363dd..7cae6c3 100644
--- a/v7/gridlayout/build.gradle
+++ b/v7/gridlayout/build.gradle
@@ -4,11 +4,23 @@
 
 dependencies {
     compile project(':support-v4')
+
+    androidTestCompile ('com.android.support.test:runner:0.4.1') {
+        exclude module: 'support-annotations'
+    }
+    androidTestCompile ('com.android.support.test.espresso:espresso-core:2.2.1') {
+        exclude module: 'support-annotations'
+    }
+    testCompile 'junit:junit:4.12'
 }
 
 android {
     compileSdkVersion project.ext.currentSdk
 
+    defaultConfig {
+        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+    }
+
     sourceSets {
         main.manifest.srcFile 'AndroidManifest.xml'
         main.java.srcDir 'src'