Update targetSdkVersion to 28

Bug: 79153175
Test: Compiled and verified that merged manifest had targetSdkVersion=28
PiperOrigin-RevId: 195145440
Change-Id: I12cde947d8fe8594f91bcc3dacdba6f9c72ac84a
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 3d8f7a4..b166895 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -21,7 +21,7 @@
 
   <uses-sdk
     android:minSdkVersion="24"
-    android:targetSdkVersion="27"/>
+    android:targetSdkVersion="28"/>
 
   <uses-permission android:name="android.permission.CALL_PHONE"/>
   <uses-permission android:name="android.permission.READ_CONTACTS"/>