libbinder: deprecated notice for *CString

These APIs are super custom and not used by AIDL. Don't
manually write parceling code, and don't use CString with
binder for sure either.

Bug: 376674798
Test: N/A
Change-Id: I8520c24f3a23f0e65e17c08e4e719dd410037c06

Author: Steven Moreland

libs/binder/include/binder/Parcel.h

@@ -178,7 +178,8 @@ class Parcel {
     LIBBINDER_EXPORTED status_t writeUint64(uint64_t val);
     LIBBINDER_EXPORTED status_t writeFloat(float val);
     LIBBINDER_EXPORTED status_t writeDouble(double val);
-    LIBBINDER_EXPORTED status_t writeCString(const char* str);
+    LIBBINDER_EXPORTED status_t writeCString(const char* str)
+            __attribute__((deprecated("use AIDL, writeString* instead")));
     LIBBINDER_EXPORTED status_t writeString8(const String8& str);
     LIBBINDER_EXPORTED status_t writeString8(const char* str, size_t len);
     LIBBINDER_EXPORTED status_t writeString16(const String16& str);
@@ -434,7 +435,8 @@ class Parcel {
     LIBBINDER_EXPORTED status_t readUtf8FromUtf16(std::unique_ptr<std::string>* str) const
             __attribute__((deprecated("use std::optional version instead")));
 
-    LIBBINDER_EXPORTED const char* readCString() const;
+    LIBBINDER_EXPORTED const char* readCString() const
+            __attribute__((deprecated("use AIDL, use readString*")));
     LIBBINDER_EXPORTED String8 readString8() const;
     LIBBINDER_EXPORTED status_t readString8(String8* pArg) const;
     LIBBINDER_EXPORTED const char* readString8Inplace(size_t* outLen) const;