media.metrics changes AString -> std::string

change from AString to std::string for how media.metrics handles
strings.  This severs the dependency on libstagefright_foundation,
where AString is implemented, so we can integrate into places
which do not want to introduce a dependency on libstagefright_foundation.

Bug: 70805723
Test: compilation/linking, CTS subset
Change-Id: I66de971b6ec354444e06112607a2d7614084cef8
diff --git a/drm/libmediadrm/PluginMetricsReporting.cpp b/drm/libmediadrm/PluginMetricsReporting.cpp
index 57ff5b8..fcff5ba 100644
--- a/drm/libmediadrm/PluginMetricsReporting.cpp
+++ b/drm/libmediadrm/PluginMetricsReporting.cpp
@@ -46,7 +46,7 @@
 
     // Report the package name.
     if (metricsGroup.has_app_package_name()) {
-      AString app_package_name(metricsGroup.app_package_name().c_str(),
+        std::string app_package_name(metricsGroup.app_package_name().c_str(),
                                metricsGroup.app_package_name().size());
       analyticsItem.setPkgName(app_package_name);
     }