libnetdutils: avoid deque<const T>

A container of const T uses std::allocator<const T>, which was an
undocumented libc++ extension that has been removed.

See llvm/llvm-project#96319.

Bug: 349681543
Test: m libnetdutils
Change-Id: I0b0eb07a6c95b4781ad04a82068bd33aef68e33b

Author: rprichard

staticlibs/netd/libnetdutils/include/netdutils/Log.h

@@ -203,7 +203,7 @@ class Log {
     void record(Level lvl, const std::string& entry);
 
     mutable std::shared_mutex mLock;
-    std::deque<const std::string> mEntries;  // GUARDED_BY(mLock), when supported
+    std::deque<std::string> mEntries;  // GUARDED_BY(mLock), when supported
 };
 
 }  // namespace netdutils