Merge pull request #349 from NordicSemiconductor/improvement/asset-path

Add asset path support

Author: philips77

lib_dfu/src/main/java/no/nordicsemi/android/dfu/DfuBaseService.java

@@ -1478,7 +1478,9 @@ private InputStream openInputStream(@NonNull final String filePath, final String
 	 */
 	private InputStream openInputStream(@NonNull final Uri stream, final String mimeType, final int mbrSize, final int types)
 			throws IOException {
-		final InputStream is = getContentResolver().openInputStream(stream);
+		final InputStream is = stream.toString().startsWith("file:///android_asset/") ?
+				getAssets().open(stream.getPath().substring(15)) :
+				getContentResolver().openInputStream(stream);
 		assert is != null;
 		if (MIME_TYPE_ZIP.equals(mimeType))
 			return new ArchiveInputStream(is, mbrSize, types);