Web view in KITKAT Video autoplay not working only show the thumbnail

Question

Setting of webview

if (Build.VERSION.SDK_INT >= 19) {
            webview.getSettings().setCacheMode(WebSettings.LOAD_CACHE_ELSE_NETWORK);
            webview.getSettings().setCacheMode(WebSettings.LOAD_DEFAULT);
        }
        webview.getSettings().setAllowContentAccess(true);
        webview.getSettings().setAllowUniversalAccessFromFileURLs(true);
        webview.getSettings().setAllowFileAccessFromFileURLs(true);
        webview.getSettings().setLoadWithOverviewMode(true);
        webview.getSettings().setUseWideViewPort(true);
        webview.getSettings().setJavaScriptEnabled(true);
        webview.getSettings().setJavaScriptCanOpenWindowsAutomatically(true);
         myWebview.setWebContentsDebuggingEnabled(true);
        webview.getSettings().setDomStorageEnabled(true);
        webview.getSettings().setSupportZoom(true);

        webview.getSettings().setSupportMultipleWindows(true);
        webview.getSettings().setAppCachePath(getActivity().getFilesDir().getAbsolutePath() + "/cache");
        webview.getSettings().setDatabaseEnabled(true);
        webview.getSettings().setDatabasePath(getActivity().getFilesDir().getAbsolutePath() + "/databases");

      webview.getSettings().setSaveFormData(true);

        webview.getSettings().setPluginState(WebSettings.PluginState.ON);
        webview.getSettings().setAllowFileAccess(true);
        webview.setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY);
        webview.getSettings().setMediaPlaybackRequiresUserGesture(false);
        webview.getSettings().setSupportMultipleWindows(true);

        if (Build.VERSION.SDK_INT >= 21) {
            webview.getSettings().setMixedContentMode(WebSettings.MIXED_CONTENT_ALWAYS_ALLOW);

        }
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            webview.setLayerType(View.LAYER_TYPE_HARDWARE, null);
        } else {
            webview.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
        }


        webview.getSettings().setAppCacheEnabled(true);
        webview.getSettings().setLoadsImagesAutomatically(true);
        webview.setWebChromeClient(new WebChromeClientCustomPoster());

        webview.getSettings().setUserAgentString("Mozilla/5.0 (Linux; Android 4.4; Nexus 5 Build/_BuildID_) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/30.0.0.0 Mobile Safari/537.36");

But web view to show the only thumbnail of the video Problem only in kitkat