BUILD_NUMBER and BUILD_HOSTNAME doesn't affect kati regeneration

* Extract BUILD_NUMBER, BUILD_HOSTNAME to file to avoid kati change
* Handle FILE_NAME_TAG_PLACEHOLDER string in dist in build/make/packaging/distdir.mk

Test: check if kati isn't invoked even though BUILD_NUMBER, BUILD_HOSTNAME
  is changed
Test: m && m, and check if the second m is no-op
Bug: 278060169
Change-Id: I1b37760242853c1a145bad255d0bb15524234b25
Merged-In: I1b37760242853c1a145bad255d0bb15524234b25
diff --git a/core/config.mk b/core/config.mk
index e272389..beb542e 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -856,6 +856,7 @@
 .KATI_READONLY := MAINLINE_SEPOLICY_DEV_CERTIFICATES
 
 BUILD_NUMBER_FROM_FILE := $$(cat $(SOONG_OUT_DIR)/build_number.txt)
+BUILD_HOSTNAME_FROM_FILE := $$(cat $(SOONG_OUT_DIR)/build_hostname.txt)
 BUILD_DATETIME_FROM_FILE := $$(cat $(BUILD_DATETIME_FILE))
 
 # SEPolicy versions