fix(android): don't set EXTRA_MIME_TYPES when using 'Any' media type on Android

Currently everything except images and videos is not selectable (text for example).
This commit fixes it and partly reverts changes made in NativeScript#290 and NativeScript#291.

Author: xuhcc

src/imagepicker.android.ts

@@ -227,19 +227,13 @@ export class ImagePicker {
             let intent = new Intent();
             intent.setType(this.mediaType);
 
-            let length  = this.mediaType === "*/*" ? 2 : 1;
-            let mimeTypes = Array.create(java.lang.String, length);
-
-            if (this.mediaType === "*/*") {
-                mimeTypes[0] = "image/*";
-                mimeTypes[1] = "video/*";
-            }
-            else {
+            if (this.mediaType !== '*/*') {
+                let mimeTypes = Array.create(java.lang.String, 1);
                 mimeTypes[0] = this.mediaType;
+                // not in platform-declaration typings
+                intent.putExtra((android.content.Intent as any).EXTRA_MIME_TYPES, mimeTypes);
             }
 
-            // not in platform-declaration typings
-            intent.putExtra((android.content.Intent as any).EXTRA_MIME_TYPES, mimeTypes);
             // TODO: Use (<any>android).content.Intent.EXTRA_ALLOW_MULTIPLE
             if (this.mode === 'multiple') {
                 intent.putExtra("android.intent.extra.ALLOW_MULTIPLE", true);