Update FileProvider sample's target SDK

This commit updates the targetSdkVersion in the
build.gradle file of the FileProvider sample.

- Updated targetSdkVersion from 30 to 31
- Added exported=true to MainActivity

Author: cartland

FileProvider/app/build.gradle

@@ -19,13 +19,12 @@ apply plugin: 'kotlin-android'
 apply plugin: 'kotlin-android-extensions'
 
 android {
-    compileSdkVersion 30
-    buildToolsVersion "30.0.3"
+    compileSdkVersion 31
 
     defaultConfig {
         applicationId "com.example.graygallery"
         minSdkVersion 21
-        targetSdkVersion 30
+        targetSdkVersion 31
         versionCode 1
         versionName "1.0"
 

FileProvider/app/src/main/AndroidManifest.xml

@@ -39,7 +39,8 @@
 
         <activity
             android:name=".MainActivity"
-            android:label="@string/app_name">
+            android:exported="true"
+            >
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />