Add the shared-storage backup component to the build

Oops.  Fixes bug 5341264

Change-Id: I99c51226c236c40bf56b1b94917f0eff56502963
diff --git a/target/product/core.mk b/target/product/core.mk
index ef34eee..ca5858f 100644
--- a/target/product/core.mk
+++ b/target/product/core.mk
@@ -39,6 +39,7 @@
     PackageInstaller \
     PicoTts \
     SettingsProvider \
+    SharedStorageBackup \
     TelephonyProvider \
     TtsService \
     UserDictionaryProvider \