Rename theme/private to theme/hidden.

private is a reserved word in java.

Test: tap
PiperOrigin-RevId: 198089995
Change-Id: I8e7efad0a8fed747466593dc7ddf1884f50fa9ac
diff --git a/packages.mk b/packages.mk
index 3767e3c..91d68c1 100644
--- a/packages.mk
+++ b/packages.mk
@@ -71,7 +71,7 @@
 	com.android.dialer.theme.base \
 	com.android.dialer.theme.base.impl \
 	com.android.dialer.theme.common \
-	com.android.dialer.theme.private \
+	com.android.dialer.theme.hidden \
 	com.android.dialer.util \
 	com.android.dialer.voicemail.listui \
 	com.android.dialer.voicemail.listui.error \