refactor

Based on Emma's suggestion, removing the `SizeOfLengthField` method and `TryBeginReadInternal` check within the ReadValueSafe (string) method and replacing that with `ReadLengthSafe`.

Author: NoelStephensUnity

com.unity.netcode.gameobjects/Runtime/Serialization/FastBufferReader.cs

@@ -654,13 +654,7 @@ public unsafe void ReadValueSafe(out string s, bool oneByteChars = false)
             }
 #endif
 
-            if (!TryBeginReadInternal(SizeOfLengthField()))
-            {
-                throw new OverflowException("Reading past the end of the buffer");
-            }
-
-
-            ReadLength(out int length);
+            ReadLengthSafe(out int length);
 
             // Validate the string's byte count based on the character count and if it is valid begin reading based on the returned
             // byte count.
@@ -673,9 +667,6 @@ public unsafe void ReadValueSafe(out string s, bool oneByteChars = false)
             ReadString(out s, length, oneByteChars);
         }
 
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        private static int SizeOfLengthField() => sizeof(uint);
-
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         private void ReadLengthSafe(out uint length) => ReadUnmanagedSafe(out length);