Fixes a bug where Gradle daemon would keep a terminated instance of A…

…DB causing it to be completely unusable

fork-runner/src/main/java/com/shazam/fork/Fork.java

@@ -19,7 +19,7 @@
 
 import static com.shazam.fork.injector.ConfigurationInjector.setConfiguration;
 import static com.shazam.fork.injector.ForkRunnerInjector.forkRunner;
-import static com.shazam.fork.injector.system.AdbInjector.adb;
+import static com.shazam.fork.injector.system.AdbInjector.releaseAdb;
 import static com.shazam.fork.utils.Utils.millisSinceNanoTime;
 import static java.lang.System.nanoTime;
 import static org.apache.commons.io.FileUtils.deleteDirectory;
@@ -50,7 +50,7 @@ public boolean run() {
 		} finally {
             long duration = millisSinceNanoTime(startOfTestsMs);
             logger.info(formatPeriod(0, duration, "'Total time taken:' H 'hours' m 'minutes' s 'seconds'"));
-            adb().terminate();
+            releaseAdb();
 		}
 	}
 }

fork-runner/src/main/java/com/shazam/fork/injector/system/AdbInjector.java

@@ -17,11 +17,22 @@
 import static com.shazam.fork.injector.ConfigurationInjector.configuration;
 
 public class AdbInjector {
-    private static final Adb ADB = new Adb(configuration().getAndroidSdk());
+    private static Adb ADB;
 
-    private AdbInjector() {}
+    private AdbInjector() {
+    }
 
     public static Adb adb() {
+        if (ADB == null) {
+            ADB = new Adb(configuration().getAndroidSdk());
+        }
         return ADB;
     }
+
+    public static void releaseAdb() {
+        if (ADB != null) {
+            ADB.terminate();
+        }
+        ADB = null;
+    }
 }