sdcard: Use std::map.

Having CaseInsensitiveCompare use strcasecomp is not ideal, but other
solutions are not prettier.

Also, add a TODO to fix FUSE_TRACE, broken by the switch to C++.

Bug: 27147273

Change-Id: I0017c3a7d0254eb81abd128b97cd06c5ad0d1dff
diff --git a/sdcard/fuse.cpp b/sdcard/fuse.cpp
index 1b6a5f1..9b1b190 100644
--- a/sdcard/fuse.cpp
+++ b/sdcard/fuse.cpp
@@ -275,8 +275,9 @@
     case PERM_ANDROID_DATA:
     case PERM_ANDROID_OBB:
     case PERM_ANDROID_MEDIA:
-        appid = (appid_t) (uintptr_t) hashmapGet(fuse->global->package_to_appid, node->name);
-        if (appid != 0) {
+        const auto& iter = fuse->global->package_to_appid->find(node->name);
+        if (iter != fuse->global->package_to_appid->end()) {
+            appid = iter->second;
             node->uid = multiuser_get_uid(parent->userid, appid);
         }
         break;