android: always specify abiFilter if not set

Specifies abiFilter to the supported architectures if it's not set.
This enables the plugin to be used on older versions of
cordova-android that might try to build unsupported architectures.

src/android/build.gradle

@@ -30,6 +30,12 @@ android {
     }
 }
 
+if (android.defaultConfig.ndk.abiFilters == null) {
+    // No abiFilter is defined for the build. Set it to the supported architectures.
+    logger.warn("nodejs-mobile-cordova detected no ABI filters were set. Will use [\"armeabi-v7a\", \"x86\", \"arm64-v8a\", \"x86_64\"].");
+    android.defaultConfig.ndk.abiFilters = ["armeabi-v7a", "x86", "arm64-v8a", "x86_64"] as Set<String>;
+}
+
 cdvPluginPostBuildExtras += { ->
     // gzip files will cause errors with aapt. Remove them for improved npm compatibility.
     android.aaptOptions.ignoreAssetsPattern += ":!*.gz";
@@ -101,13 +107,7 @@ if ("1".equals(shouldRebuildNativeModules)) {
         }
     }
 
-    def nativeModulesABIs = android.defaultConfig.ndk.abiFilters;
-    if (nativeModulesABIs == null) {
-        // No abiFilter is defined for the build. Build native modules for every architecture.
-        nativeModulesABIs = ["armeabi-v7a", "x86", "arm64-v8a", "x86_64"] as Set<String>;
-    }
-
-    nativeModulesABIs.each { abi_name ->
+    android.defaultConfig.ndk.abiFilters.each { abi_name ->
         String temp_arch = {
             switch (abi_name) {
                 case 'armeabi-v7a':