Address const issues in preparation for libcxx rebase.

Change-Id: I61777e557738b2df8b6037a6f71a2cf0a24967dd
diff --git a/media/libstagefright/httplive/M3UParser.cpp b/media/libstagefright/httplive/M3UParser.cpp
index ff2bb27..4969b2a 100644
--- a/media/libstagefright/httplive/M3UParser.cpp
+++ b/media/libstagefright/httplive/M3UParser.cpp
@@ -498,8 +498,8 @@
     if (url[0] == '/') {
         // URL is an absolute path.
 
-        char *protocolEnd = strstr(baseURL, "//") + 2;
-        char *pathStart = strchr(protocolEnd, '/');
+        const char *protocolEnd = strstr(baseURL, "//") + 2;
+        const char *pathStart = strchr(protocolEnd, '/');
 
         if (pathStart != NULL) {
             out->setTo(baseURL, pathStart - baseURL);