New OnceUx Test Class CompanionAdTestCase.java

##Rationale
Now that Companion Ads have been implemented into the Sample App, It's time for tests.
##Changed Files
**CompanionAdTestCase.java**
* New utility methods
    * *companionCheck* finds the companion ad based on the companion ad frame's resource id
    * *toCompanionAdCheck(int msec)* navigates to the next ad break, then performs *companionCheck*. It returns the results of *companionCheck*.
    * *toEndOfAdBreak* navigates to the end of an ad break, hides the seek controls, and then performs *companionCheck*. It returns the results of *companionCheck*.
* New tests
    * **testCompanionAd** navigates through the video using *toCompanionAdCheck* and *toEndOfAdBreak*. After the start of each ad break, it asserts that the companion ad is present.
    * **testCompanionAdLink** clicks on a companion ad and tests for the presence of the browser url the click is meant to link to
    * **testCompanionAdVanish** navigates through the video using *toCompanionAdCheck* and *toEndOfAdBreak*, checking after the end of each ad break for the presence of a companion ad. It asserts that *toEndOfAdBreak* will return false for each ad break.
I guess I'd like to see how these timeout methods behave. Have you seen them break things badly (e.g. crashing the UIAutomator) when a timeout does occur? I've seen in our other frameworks here that if we wait for a component to be available (clickable, visible, whatever) and it doesn't, the timeout occurs, the test aborts and logs an error.
I've not written tests using either UIAutomator or the Android JUnit framework, so I can't say for sure that they're not behaving differently, though.