updater_sample: add updater state

- Add util.UpdaterStates - the state of SystemUpdaterSample.
    It's different from status of UpdateEngine;
    when UpdateEngine#cancel is used to suspend the update,
    UpdateEngine sets status to IDLE, which cannot be used
    to track the suspended state.
- UI: Change 'Update status' to 'Engine status'.
- UI: Change 'Update completion' to 'Engine error code'.
- UI: Add 'Updater state'.

Test: manually on the device
Test: using JUnit4
Change-Id: I9c58b5ed0eae3be7ab8b217fc01a621e8fb2f4bf
Signed-off-by: Zhomart Mukhamejanov <zhomart@google.com>
diff --git a/updater_sample/src/com/example/android/systemupdatersample/util/UpdateEngineErrorCodes.java b/updater_sample/src/com/example/android/systemupdatersample/util/UpdateEngineErrorCodes.java
index f06ddf7..7d55ff8 100644
--- a/updater_sample/src/com/example/android/systemupdatersample/util/UpdateEngineErrorCodes.java
+++ b/updater_sample/src/com/example/android/systemupdatersample/util/UpdateEngineErrorCodes.java
@@ -36,6 +36,7 @@
     */
     public static final int UNKNOWN = -1;
     public static final int UPDATED_BUT_NOT_ACTIVE = 52;
+    public static final int USER_CANCELLED = 48;
 
     private static final SparseArray<String> CODE_TO_NAME_MAP = new SparseArray<>();
 
@@ -61,7 +62,7 @@
      * Completion codes returned by update engine indicating that the update
      * was successfully applied.
      */
-    private static final Set<Integer> SUCCEEDED_COMPLETION_CODES = new HashSet<Integer>(
+    private static final Set<Integer> SUCCEEDED_COMPLETION_CODES = new HashSet<>(
             Arrays.asList(UpdateEngine.ErrorCodeConstants.SUCCESS,
                     // UPDATED_BUT_NOT_ACTIVE is returned when the payload is
                     // successfully applied but the