Upgrade target SDK version to 27.

Test: None
PiperOrigin-RevId: 179458302
Change-Id: Ic6bfd4abe4c7f51d395488863edc1515754f6b36
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index d1585e0..b459a44 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -21,7 +21,7 @@
 
   <uses-sdk
     android:minSdkVersion="23"
-    android:targetSdkVersion="26"/>
+    android:targetSdkVersion="27"/>
 
   <uses-permission android:name="android.permission.CALL_PHONE"/>
   <uses-permission android:name="android.permission.READ_CONTACTS"/>