Use String8/16 c_str [mtp]

Bug: 295394788
Test: make checkbuild
Change-Id: If578a11f6b6805e1ae9364437d09b3d854fef0df
diff --git a/media/mtp/tests/MtpFuzzer/mtp_data_packet_fuzzer.cpp b/media/mtp/tests/MtpFuzzer/mtp_data_packet_fuzzer.cpp
index f5faf77..83c6076 100644
--- a/media/mtp/tests/MtpFuzzer/mtp_data_packet_fuzzer.cpp
+++ b/media/mtp/tests/MtpFuzzer/mtp_data_packet_fuzzer.cpp
@@ -212,7 +212,7 @@
                     if (mFdp.ConsumeBool()) {
                         std::string str = mFdp.ConsumeRandomLengthString(kMaxLength);
                         android::String16 s(str.c_str());
-                        char16_t* data = const_cast<char16_t*>(s.string());
+                        char16_t* data = const_cast<char16_t*>(s.c_str());
                         mtpDataPacket.putString(reinterpret_cast<uint16_t*>(data));
                     } else {
                         mtpDataPacket.putString(static_cast<uint16_t*>(nullptr));
diff --git a/media/mtp/tests/MtpFuzzer/mtp_property_fuzzer.cpp b/media/mtp/tests/MtpFuzzer/mtp_property_fuzzer.cpp
index b4e659c..6300256 100644
--- a/media/mtp/tests/MtpFuzzer/mtp_property_fuzzer.cpp
+++ b/media/mtp/tests/MtpFuzzer/mtp_property_fuzzer.cpp
@@ -101,7 +101,7 @@
                     std::string str = mFdp.ConsumeRandomLengthString(kMaxLength);
                     android::String16 s(str.c_str());
                     if (mFdp.ConsumeBool()) {
-                        data = const_cast<char16_t*>(s.string());
+                        data = const_cast<char16_t*>(s.c_str());
                     }
 
                     if (mFdp.ConsumeBool()) {