Add a mount with metadata encryption service

Don't use the FDE flow to support metadata encryption; just provide a
vold service which directly mounts the volume and use that.

Bug: 63927601
Test: Boot Taimen to SUW with and without metadata encryption.
Change-Id: Ifc6a012c02c0ea66893020ed1d0da4cba6914aed
diff --git a/main.cpp b/main.cpp
index 62ea6b7..5525e85 100644
--- a/main.cpp
+++ b/main.cpp
@@ -51,12 +51,14 @@
 using android::base::StringPrintf;
 
 int main(int argc, char** argv) {
+    atrace_set_tracing_enabled(false);
     setenv("ANDROID_LOG_TAGS", "*:v", 1);
     android::base::InitLogging(argv, android::base::LogdLogger(android::base::SYSTEM));
 
+    LOG(INFO) << "Vold 3.0 (the awakening) firing up";
+
     ATRACE_BEGIN("main");
 
-    LOG(INFO) << "Vold 3.0 (the awakening) firing up";
 
     LOG(VERBOSE) << "Detected support for:"
             << (android::vold::IsFilesystemSupported("ext4") ? " ext4" : "")
@@ -113,6 +115,8 @@
     }
     ATRACE_END();
 
+    LOG(DEBUG) << "VoldNativeService::start() completed OK";
+
     ATRACE_BEGIN("NetlinkManager::start");
     if (nm->start()) {
         PLOG(ERROR) << "Unable to start NetlinkManager";