Migrate String8/16 from .string() to c_str()

This will align usage with std::string.

Bug: 295394788
Test: make checkbuild
Change-Id: Ic5c215b011197950dcbcb0339f44cc68fefc65a1
diff --git a/libutils/String16_fuzz.cpp b/libutils/String16_fuzz.cpp
index d7e5ec7..a271aee 100644
--- a/libutils/String16_fuzz.cpp
+++ b/libutils/String16_fuzz.cpp
@@ -25,7 +25,7 @@
 
                 // Bytes and size
                 ([](FuzzedDataProvider&, android::String16 str1, android::String16) -> void {
-                    str1.string();
+                    str1.c_str();
                 }),
                 ([](FuzzedDataProvider&, android::String16 str1, android::String16) -> void {
                     str1.isStaticString();
@@ -39,7 +39,7 @@
                     str1.startsWith(str2);
                 }),
                 ([](FuzzedDataProvider&, android::String16 str1, android::String16 str2) -> void {
-                    str1.contains(str2.string());
+                    str1.contains(str2.c_str());
                 }),
                 ([](FuzzedDataProvider&, android::String16 str1, android::String16 str2) -> void {
                     str1.compare(str2);
@@ -52,7 +52,7 @@
                 ([](FuzzedDataProvider& dataProvider, android::String16 str1,
                     android::String16 str2) -> void {
                     int pos = dataProvider.ConsumeIntegralInRange<int>(0, str1.size());
-                    str1.insert(pos, str2.string());
+                    str1.insert(pos, str2.c_str());
                 }),
 
                 // Find and replace operations