Use String8/16 c_str

Bug: 295394788
Test: make checkbuild
Change-Id: I538720d4de2dcc038b417048209782ff605b7e30
diff --git a/native/android/asset_manager.cpp b/native/android/asset_manager.cpp
index 69cf804..1878716 100644
--- a/native/android/asset_manager.cpp
+++ b/native/android/asset_manager.cpp
@@ -118,7 +118,7 @@
     // the string to return and advance the iterator for next time.
     if (index < max) {
         assetDir->mCachedFileName = assetDir->mAssetDir->getFileName(index);
-        returnName = assetDir->mCachedFileName.string();
+        returnName = assetDir->mCachedFileName.c_str();
         index++;
     }
 
@@ -134,7 +134,7 @@
 const char* AAssetDir_getFileName(AAssetDir* assetDir, int index)
 {
     assetDir->mCachedFileName = assetDir->mAssetDir->getFileName(index);
-    return assetDir->mCachedFileName.string();
+    return assetDir->mCachedFileName.c_str();
 }
 
 void AAssetDir_close(AAssetDir* assetDir)