crash_reporter: Change the crash server url to an os-release.d field

Bug: 24989289
Change-Id: Ib90e4a8e27d946c6330b60cd6de432d25adef05e
diff --git a/ledflasher.mk b/ledflasher.mk
index 4b4919f..f23c166 100644
--- a/ledflasher.mk
+++ b/ledflasher.mk
@@ -35,6 +35,5 @@
 # metrics/crash reports to the right customer.
 BRILLO_PRODUCT_ID := developer-boards:brillo-starter-board-qualcomm
 
-# Adds some product specific properties.
-PRODUCT_PROPERTY_OVERRIDES += \
-  crash_reporter.server=https://clients2.google.com/bc/report \
+# Set the crash server URL.
+BRILLO_CRASH_SERVER := https://clients2.google.com/bc/report