Update API parameter from char** to const char* const*

AIBinder_Class_setTransactionCodeToFunctionNameMap takes in char**
pointer and rust wrapper requires a mutable array due to this.
API doesn't modify the char** array anyway. Updating it to use
const char* const*.

Test: m libbinder_ndk && m
Test: m CtsNdkBinderTestCases && atest -c CtsNdkBinderTestCases
Bug: 394661050
Flag: EXEMPT NDK change
Change-Id: I78adbee923071d6295fdb8e2f3431f20073a40eb