Add implicit conversion operator to std::string_view

android::base::Trim has been updated to take a std::string_view instead
of a const std::string&. Remove explicit conversions to std::string for
Trim arguments so that we do not create a unnecessary copies for the T ->
std::string conversion, only to implicitly convert from std::string ->
std::string_view immediately after.

Bug: N/A
Test: Still builds
Change-Id: Ib3db6f652f5a2b84f89cf130e3cf4a7acf9f185b
diff --git a/media/mtp/MtpServer.cpp b/media/mtp/MtpServer.cpp
index 6fcf119..d917772 100644
--- a/media/mtp/MtpServer.cpp
+++ b/media/mtp/MtpServer.cpp
@@ -985,7 +985,7 @@
 
     int type = storage->getType();
     if (type == MTP_STORAGE_REMOVABLE_RAM) {
-        std::string str = android::base::Trim((const char*)name);
+        std::string str = android::base::Trim(name);
         name.set(str.c_str());
     }
     ALOGV("name: %s format: 0x%04X (%s)\n", (const char*)name, format,
diff --git a/media/mtp/MtpStringBuffer.h b/media/mtp/MtpStringBuffer.h
index 4cec58a..30d1bc1 100644
--- a/media/mtp/MtpStringBuffer.h
+++ b/media/mtp/MtpStringBuffer.h
@@ -20,6 +20,7 @@
 #include <log/log.h>
 #include <stdint.h>
 #include <string>
+#include <string_view>
 
 // Max Character number of a MTP String
 #define MTP_STRING_MAX_CHARACTER_NUMBER             255
@@ -55,6 +56,7 @@
     inline int      size() const { return mString.length(); }
 
     inline operator const char*() const { return mString.c_str(); }
+    operator std::string_view() const { return mString; }
 };
 
 inline void MtpStringBuffer::append(const char* other) {