fix: remove unnecessary contextcompat class lookup (#2091)

AWSMobileClient tried to check if the library has network access. As
part of this, it checks whether or not there is permission to access the
network. The existing mechanism to achieve this performed a reflective
class lookup on an (old) Android support library.

Instead, guard the checkSelfPermission(..) call in an API level guard.

Resolves: #2063

Author: jamesonwilliams

aws-android-sdk-mobile-client/src/main/java/com/amazonaws/mobile/client/AWSMobileClient.java

@@ -26,6 +26,8 @@
 import android.net.ConnectivityManager;
 import android.net.NetworkInfo;
 import android.net.Uri;
+import android.os.Build;
+import android.util.Log;
 import androidx.annotation.AnyThread;
 import androidx.annotation.WorkerThread;
 import androidx.browser.customtabs.CustomTabsCallback;
@@ -34,7 +36,6 @@
 import androidx.browser.customtabs.CustomTabsServiceConnection;
 import androidx.browser.customtabs.CustomTabsSession;
 import androidx.core.content.ContextCompat;
-import android.util.Log;
 
 import com.amazonaws.AmazonClientException;
 import com.amazonaws.ClientConfiguration;
@@ -767,15 +768,12 @@ public void run() {
      * @return true if permission to access network state is granted and network is connected.
      */
     protected boolean isNetworkAvailable(final Context context) {
-        try {
-            Class.forName("android.support.v4.content.ContextCompat");
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
             int hasReadExternalStoragePermission = ContextCompat.checkSelfPermission(context,
                     Manifest.permission.ACCESS_NETWORK_STATE);
             if (hasReadExternalStoragePermission != PackageManager.PERMISSION_GRANTED) {
                 return false;
             }
-        } catch (ClassNotFoundException e) {
-            Log.w(TAG, "Could not check if ACCESS_NETWORK_STATE permission is available.", e);
         }
 
         try {
@@ -3989,4 +3987,4 @@ Uri exchangeCode(String uri) {
         return null;
     }
 
-}
+}