Add vendor prefix to slpi property

For devices launching with Android Q or later, properties defined by
vendor should have the prefix "vendor."

Bug: 138278883
Test: m
Change-Id: I728b4d8ab2f46936e7954bece94e53e6628992fb
diff --git a/init.qcom.devstart.sh b/init.qcom.devstart.sh
index 3589ac2..9650775 100644
--- a/init.qcom.devstart.sh
+++ b/init.qcom.devstart.sh
@@ -7,4 +7,4 @@
 version=`grep -ao "OEM_IMAGE_VERSION_STRING[ -~]*" \
               /vendor/firmware/slpi_v2.b04 | \
          sed -e s/OEM_IMAGE_VERSION_STRING=SLPI.version.// -e s/\(.*\).//`
-setprop sys.slpi.firmware.version "$version"
+setprop vendor.sys.slpi.firmware.version "$version"
diff --git a/sepolicy/vendor/property_contexts b/sepolicy/vendor/property_contexts
index 01019b2..49135b0 100644
--- a/sepolicy/vendor/property_contexts
+++ b/sepolicy/vendor/property_contexts
@@ -65,7 +65,7 @@
 # They are public_vendor_system_props for vendor-specific extension.
 sys.all.modules.ready      u:object_r:public_vendor_system_prop:s0
 sys.qcom.devup             u:object_r:public_vendor_system_prop:s0
-sys.slpi.firmware.version  u:object_r:public_vendor_system_prop:s0
+vendor.sys.slpi.firmware.version  u:object_r:public_vendor_system_prop:s0
 
 # vendor_default_prop
 # default_prop isn't accessible from vendor components.