Remove system library classes from DataSourceBase

Test: build.
Bug: 67908556
Change-Id: Ib56b3cd92ecc781fc2c4ff3696e71051ce8e212d
diff --git a/media/libmediaextractor/DataSourceBase.cpp b/media/libmediaextractor/DataSourceBase.cpp
index d3af4eb..8f47ee5 100644
--- a/media/libmediaextractor/DataSourceBase.cpp
+++ b/media/libmediaextractor/DataSourceBase.cpp
@@ -123,8 +123,8 @@
     return ERROR_UNSUPPORTED;
 }
 
-String8 DataSourceBase::getMIMEType() const {
-    return String8("application/octet-stream");
+bool DataSourceBase::getUri(char *uriString __unused, size_t bufferSize __unused) {
+    return false;
 }
 
 }  // namespace android