Revert "Adding GSI keys"

This reverts commit 421986004d9044f8deed5aa4e90be27dda4d01c8.
Wahoo has no first-stage ramdisk and there is no need to install
GSI keys there.

Bug: 140873290
Test: tree hugger

Change-Id: I4dfe0bb0d88dbbbcaa6742cef9f2405d3b7936d6
diff --git a/device.mk b/device.mk
index d6c1313..d40318c 100755
--- a/device.mk
+++ b/device.mk
@@ -14,9 +14,6 @@
 # limitations under the License.
 #
 
-# Installs gsi keys into ramdisk, to boot a GSI with verified boot.
-$(call inherit-product, $(SRC_TARGET_DIR)/product/gsi_keys.mk)
-
 # Enable updating of APEXes
 $(call inherit-product, $(SRC_TARGET_DIR)/product/updatable_apex.mk)