Ffmpeg native android lib included ABIS for x64 and x86 CPU's -> Flut…

…ter recognized x64 ABIS and build the whole project trageting that CPU Architecture. However that caused startup failure on non-x64 CPUS

--> only included the armeabi-v7 instead of all types

- Also APK size shrinked to 50%
See:
flutter/flutter#18494

android/app/build.gradle

@@ -51,6 +51,9 @@ android {
     }
     buildTypes {
         release {
+            ndk{
+                abiFilters 'armeabi-v7a'
+            }
             signingConfig signingConfigs.release
         }
     }
@@ -65,7 +68,7 @@ dependencies {
     androidTestImplementation 'com.android.support.test:runner:1.0.1'
     androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
     implementation 'com.android.support:appcompat-v7:27.1.1'
-    implementation(name:'all-fmmr', ext:'aar')
+    implementation(name:'armv7-fmmr', ext:'aar')
     // full exoplayer library
     compile 'com.google.android.exoplayer:exoplayer:2.8.1'
 }

android/app/src/main/java/com/yourcompany/flutterws/video/VideoStreamHandler.java

@@ -43,11 +43,10 @@ public void onCancel(Object o) {
     public void startPreviewTask(String url, String fileName, String videoId) {
 
         Runnable task = () -> {
-
             FFmpegMediaMetadataRetriever mmr = new FFmpegMediaMetadataRetriever();
             Bitmap preview;
 
-            if (fileName != null){
+            if (fileName != null) {
 
                 File file = new File(Environment.getExternalStorageDirectory() + "/MediathekView", fileName);
                 Log.i(TAG, "Starting task: preview video with fileName" + fileName + ". File: Can Read: " + file.canRead() + " Lenght: " + file.length());
@@ -62,8 +61,7 @@ public void startPreviewTask(String url, String fileName, String videoId) {
                     events.error(TAG, "File to generate preview from -  does not exist", null);
                     return;
                 }*/
-            }
-            else {
+            } else {
                 Log.i(TAG, "Starting task: preview video with  url : " + url);
                 mmr.setDataSource(url);
 
@@ -75,7 +73,7 @@ public void startPreviewTask(String url, String fileName, String videoId) {
             /*preview = mmr.getFrameAtTime(1000000, FFmpegMediaMetadataRetriever.OPTION_NEXT_SYNC); // frame at 2 seconds
             mmr.release();
             */
-            if (preview == null){
+            if (preview == null) {
                 Log.e(TAG, "Could not get preview bitmap");
                 events.error(TAG, "Could not get preview bitmap", null);
                 return;
@@ -89,7 +87,7 @@ public void startPreviewTask(String url, String fileName, String videoId) {
             byte[] byteArray = stream.toByteArray();
             preview.recycle();
 
-            Map<String, Object> returnArguments =new HashMap<>();
+            Map<String, Object> returnArguments = new HashMap<>();
             returnArguments.put("image", byteArray);
             returnArguments.put("videoId", videoId);