Revert "Delete Essential overlay, Essential PH-1 already has a proper vendor overlay"

This reverts commit 8d41bcf461e2775e3da06d65cb78722008de64c2.
diff --git a/Essential-PH1/Android.mk b/Essential-PH1/Android.mk
new file mode 100644
index 0000000..271d429
--- /dev/null
+++ b/Essential-PH1/Android.mk
@@ -0,0 +1,5 @@
+LOCAL_PATH := $(call my-dir)
+include $(CLEAR_VARS)
+LOCAL_MODULE_TAGS := optional
+LOCAL_PACKAGE_NAME := treble-overlay-Essential_PH1
+include $(BUILD_PACKAGE)