Keystore 2.0: Rename legacy_migrator to importer.

This refactor serves the disambiguation between the import of legacy
blobs into the sqlite3 database and the migration of keys between
namespaces, which becomes more promient in the light of shared uid
migration.

Test: No new test required because no functionality was changed.
Change-Id: I0612d0731083548a196911712f6c0adbbc9a5e9a
diff --git a/keystore2/src/globals.rs b/keystore2/src/globals.rs
index 2819314..9475cf6 100644
--- a/keystore2/src/globals.rs
+++ b/keystore2/src/globals.rs
@@ -18,7 +18,7 @@
 
 use crate::gc::Gc;
 use crate::legacy_blob::LegacyBlobLoader;
-use crate::legacy_migrator::LegacyMigrator;
+use crate::legacy_importer::LegacyImporter;
 use crate::super_key::SuperKeyManager;
 use crate::utils::watchdog as wd;
 use crate::{async_task::AsyncTask, database::MonotonicRawTime};
@@ -175,8 +175,8 @@
     pub static ref LEGACY_BLOB_LOADER: Arc<LegacyBlobLoader> = Arc::new(LegacyBlobLoader::new(
         &DB_PATH.read().expect("Could not get the database path for legacy blob loader.")));
     /// Legacy migrator. Atomically migrates legacy blobs to the database.
-    pub static ref LEGACY_MIGRATOR: Arc<LegacyMigrator> =
-        Arc::new(LegacyMigrator::new(Arc::new(Default::default())));
+    pub static ref LEGACY_IMPORTER: Arc<LegacyImporter> =
+        Arc::new(LegacyImporter::new(Arc::new(Default::default())));
     /// Background thread which handles logging via statsd and logd
     pub static ref LOGS_HANDLER: Arc<AsyncTask> = Default::default();