Use String8/16 c_str [media]

Bug: 295394788
Test: make checkbuild
Change-Id: I4ba5400f39c769bec59508525844f1daefe1d15c
diff --git a/drm/drmserver/PlugInManager.h b/drm/drmserver/PlugInManager.h
index 466844d..df40476 100644
--- a/drm/drmserver/PlugInManager.h
+++ b/drm/drmserver/PlugInManager.h
@@ -137,7 +137,7 @@
 
         PlugInContainer* pPlugInContainer = new PlugInContainer();
 
-        pPlugInContainer->hHandle = dlopen(rsPlugInPath.string(), RTLD_LAZY);
+        pPlugInContainer->hHandle = dlopen(rsPlugInPath.c_str(), RTLD_LAZY);
 
         if (NULL == pPlugInContainer->hHandle) {
             delete pPlugInContainer;
@@ -201,7 +201,7 @@
      */
     Vector<String8> getPlugInPathList(const String8& rsDirPath) {
         Vector<String8> fileList;
-        DIR* pDir = opendir(rsDirPath.string());
+        DIR* pDir = opendir(rsDirPath.c_str());
         struct dirent* pEntry;
 
         while (NULL != pDir && NULL != (pEntry = readdir(pDir))) {