Adds actions to shadow notification builder

Adds actions to ShadowNotification only at this time.

Issue with RemoteViews bitmap cache must be resolve before calling through  to real builder. Doing so currently produces the following error:

    java.lang.NullPointerException
    	at android.widget.RemoteViews.configureRemoteViewsAsChild(RemoteViews.java:1252)
    	at android.widget.RemoteViews.access$300(RemoteViews.java:63)
    	at android.widget.RemoteViews$ViewGroupAction.__constructor__(RemoteViews.java:1271)
    	at android.widget.RemoteViews$ViewGroupAction.<init>(RemoteViews.java:1267)
    	at android.widget.RemoteViews.addView(RemoteViews.java:1783)
    	at android.app.Notification$Builder.applyStandardTemplateWithActions(Notification.java:1611)
    	at android.app.Notification$Builder.makeBigContentView(Notification.java:1642)
    	at android.app.Notification$Builder.buildUnstyled(Notification.java:1683)
    	at android.app.Notification$Builder.build(Notification.java:1745)
    	at org.fest.reflect.method.Invoker.invoke(Invoker.java:112)
    	at org.robolectric.shadows.ShadowNotification$ShadowBuilder.build(ShadowNotification.java:148)
    	at android.app.Notification$Builder.build(Notification.java)
    	at org.robolectric.shadows.NotificationBuilderTest.build_addsActionToNotification(NotificationBuilderTest.java:78)
    	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
    	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
    	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
    	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
    	at org.robolectric.RobolectricTestRunner$2.evaluate(RobolectricTestRunner.java:250)
    	at org.junit.runners.BlockJUnit4ClassRunner.runNotIgnored(BlockJUnit4ClassRunner.java:79)
    	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:71)
    	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49)
    	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
    	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
    	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
    	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
    	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
    	at org.robolectric.RobolectricTestRunner$1.evaluate(RobolectricTestRunner.java:177)
    	at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
    	at org.junit.runner.JUnitCore.run(JUnitCore.java:157)
    	at com.intellij.rt.execution.application.AppMain.main(AppMain.java:134)