Fix lint issues

app/src/main/AndroidManifest.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
     package="org.solovyev.android.calculator"
     android:installLocation="auto">
 
@@ -25,7 +26,8 @@
         android:hardwareAccelerated="true"
         android:icon="@drawable/ic_launcher"
         android:label="@string/c_app_name"
-        android:theme="@style/Cpp.Theme.Material">
+        android:theme="@style/Cpp.Theme.Material"
+        tools:ignore="UnusedAttribute">
 
         <meta-data
             android:name="com.google.android.gms.version"
@@ -210,6 +212,7 @@
         <!-- Google Analytics -->
         <receiver
             android:name="com.google.android.gms.analytics.AnalyticsReceiver"
+            android:exported="false"
             android:enabled="true">
             <intent-filter>
                 <action android:name="com.google.android.gms.analytics.ANALYTICS_DISPATCH" />