Remove ro.expect.recovery_id

This is not used by anyone and the other half of the code to compare
against it is already functionally dead, so remove this.

Test: build
Change-Id: I44ed087cb7735bbc23e30b6c310c80eb3b7b6488
diff --git a/core/Makefile b/core/Makefile
index 0bbaf12..9561146 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -474,9 +474,6 @@
 $(INSTALLED_BUILD_PROP_TARGET): $(intermediate_system_build_prop) $(INSTALLED_RECOVERYIMAGE_TARGET)
 	@echo "Target build info: $@"
 	$(hide) grep -v 'ro.product.first_api_level' $(intermediate_system_build_prop) > $@
-ifdef INSTALLED_RECOVERYIMAGE_TARGET
-	$(hide) echo ro.expect.recovery_id=`cat $(RECOVERYIMAGE_ID_FILE)` >> $@
-endif
 
 # -----------------------------------------------------------------
 # vendor build.prop
diff --git a/tools/releasetools/target_files_diff.py b/tools/releasetools/target_files_diff.py
index 7415f27..4402c8d 100755
--- a/tools/releasetools/target_files_diff.py
+++ b/tools/releasetools/target_files_diff.py
@@ -71,7 +71,6 @@
              'ro.build.user=',
              'ro.build.description=',
              'ro.build.fingerprint=',
-             'ro.expect.recovery_id=',
              'ro.vendor.build.date=',
              'ro.vendor.build.date.utc=',
              'ro.vendor.build.fingerprint=']