cameraservice: Migrate all internal String8/String16s to std::string

String8 and String16 are deprecated classes. It is recommended to use
std::string or std::u16string wherever possible. String16 is the native
string class for aidl, but Strings marked @utf8InCpp can use std::string
directly.

This patch standardizes libcameraservice's use of strings to
std::string, which is capable of storing utf-8 strings. This makes the
code more readable and potentially reduces the number of string copies
to a minimum.

A new set of string utils is added to frameworks/av/camera to aid this
migration.

Change-Id: I59330ac03c8a52b6c21a2388bba0c143e68af4cf
Bug: 265487852
Test: Presubmit, ran CtsCameraTestCases on Cuttlefish, adb shell dumpsys media camera and observed output
diff --git a/services/camera/libcameraservice/api2/HeicCompositeStream.cpp b/services/camera/libcameraservice/api2/HeicCompositeStream.cpp
index 694aff3..8144792 100644
--- a/services/camera/libcameraservice/api2/HeicCompositeStream.cpp
+++ b/services/camera/libcameraservice/api2/HeicCompositeStream.cpp
@@ -29,6 +29,7 @@
 #include <gui/Surface.h>
 #include <utils/Log.h>
 #include <utils/Trace.h>
+#include <camera/StringUtils.h>
 
 #include <mediadrm/ICrypto.h>
 #include <media/MediaCodecBuffer.h>
@@ -98,17 +99,17 @@
     status_t err;
     int format;
     if ((err = anw->query(anw, NATIVE_WINDOW_FORMAT, &format)) != OK) {
-        String8 msg = String8::format("Failed to query Surface format: %s (%d)", strerror(-err),
+        std::string msg = fmt::sprintf("Failed to query Surface format: %s (%d)", strerror(-err),
                 err);
-        ALOGE("%s: %s", __FUNCTION__, msg.string());
+        ALOGE("%s: %s", __FUNCTION__, msg.c_str());
         return false;
     }
 
     int dataspace;
     if ((err = anw->query(anw, NATIVE_WINDOW_DEFAULT_DATASPACE, &dataspace)) != OK) {
-        String8 msg = String8::format("Failed to query Surface dataspace: %s (%d)", strerror(-err),
+        std::string msg = fmt::sprintf("Failed to query Surface dataspace: %s (%d)", strerror(-err),
                 err);
-        ALOGE("%s: %s", __FUNCTION__, msg.string());
+        ALOGE("%s: %s", __FUNCTION__, msg.c_str());
         return false;
     }
 
@@ -117,7 +118,7 @@
 
 status_t HeicCompositeStream::createInternalStreams(const std::vector<sp<Surface>>& consumers,
         bool /*hasDeferredConsumer*/, uint32_t width, uint32_t height, int format,
-        camera_stream_rotation_t rotation, int *id, const String8& physicalCameraId,
+        camera_stream_rotation_t rotation, int *id, const std::string& physicalCameraId,
         const std::unordered_set<int32_t> &sensorPixelModesUsed,
         std::vector<int> *surfaceIds,
         int /*streamSetId*/, bool /*isShared*/, int32_t colorSpace,