Revert "Base: Delete ostream<< with std::string*"

This reverts commit 4ef5011a7b.

Reason for revert: Breaks an internal mocking case that cannot be changed.

Test: m
Change-Id: I83f9338bde02eb2b45b3e52b66ef78490ddbeeda

base/include/android-base/logging.h

@@ -438,14 +438,4 @@ class ScopedLogSeverity {
 }  // namespace base
 }  // namespace android
 
-namespace std {
-
-// Delete << with string* to avoid mistakes. The intention was most likely to print *string.
-// If you really want to print the pointer, consider static_cast<void*>.
-//
-// Note: for this to work, we need to have this in a namespace.
-std::ostream& operator<<(std::ostream& stream, const std::string* string_pointer) = delete;
-
-}  // namespace std
-
 #endif  // ANDROID_BASE_LOGGING_H