Consume driver awareness values from suppliers

- Create interfaces for DriverAwarenessSuppliers and callbacks
- Create a demo implementation for touch supplier
- Handle prioritiziation of multiple awareness suppliers
- Handle refreshing driver awareness value when data becomes stale
- Logging / dumpsys information for debugging

Bug: 143492965
Bug: 143493041
Test: atest DriverDistractionExperimentalFeatureServiceTest

// enable feature
$ adb root; adb shell dumpsys car_service enable-feature android.car.experimental.driver_distraction_experimental_feature_service; adb reboot

// check dumpsys
$ adb shell dumpsys activity service ExperimentalCarService

Change-Id: Ic13b2408d646a22ba6a4eb0012313fd685d6c8f9
diff --git a/service/Android.bp b/service/Android.bp
index 0035441..d9a915b 100644
--- a/service/Android.bp
+++ b/service/Android.bp
@@ -76,6 +76,7 @@
         "src/com/android/car/CarServiceBase.java",
         "src/com/android/car/CarServiceUtils.java",
         "src/com/android/car/CarLog.java",
+        "src/com/android/car/Utils.java",
     ],
 
     product_variables: {