package refactor (#534)

* Implement Firebase segmentation SDK device local cache

* [Firebase Segmentation] Add custom installation id cache layer and tests for it.

* Add test for updating cache

* Switch to use SQLiteOpenHelper

* Switch to use SharedPreferences from SQLite.

* Change the cache class to be singleton

* Wrap shared pref commit in a async task.

* Address comments

* Google format fix

* Replace some deprecated code.

* Package refactor

* nit

* nit

Author: diwu-arete

firebase-segmentation/src/androidTest/java/com/google/firebase/segmentation/CustomInstallationIdCacheTest.java renamed to firebase-segmentation/src/androidTest/java/com/google/firebase/segmentation/local/CustomInstallationIdCacheTest.java

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package com.google.firebase.segmentation;
+package com.google.firebase.segmentation.local;
 
 import static com.google.common.truth.Truth.assertThat;
 import static org.junit.Assert.assertNull;

firebase-segmentation/src/main/java/com/google/firebase/segmentation/CustomInstallationIdCache.java renamed to firebase-segmentation/src/main/java/com/google/firebase/segmentation/local/CustomInstallationIdCache.java

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package com.google.firebase.segmentation;
+package com.google.firebase.segmentation.local;
 
 import android.content.Context;
 import android.content.SharedPreferences;

firebase-segmentation/src/main/java/com/google/firebase/segmentation/CustomInstallationIdCacheEntryValue.java renamed to firebase-segmentation/src/main/java/com/google/firebase/segmentation/local/CustomInstallationIdCacheEntryValue.java

@@ -12,10 +12,10 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package com.google.firebase.segmentation;
+package com.google.firebase.segmentation.local;
 
 import com.google.auto.value.AutoValue;
-import com.google.firebase.segmentation.CustomInstallationIdCache.CacheStatus;
+import com.google.firebase.segmentation.local.CustomInstallationIdCache.CacheStatus;
 
 /**
  * This class represents a cache entry value in {@link CustomInstallationIdCache}, which contains a