sibon: Add Browser2 to exclusion list

This is an unmaintained project from AOSP and hence
has been removed from manifest.

Add this to the exclusion list while checking for existance of
all PRODUCT_PACKAGES components.

Issue: FP3-A13#2
Change-Id: I6eca8c2c11b6f4f0d45cf1a5ad65c9d5be4f1d23
diff --git a/fp3_sibon.mk b/fp3_sibon.mk
index e07386a..b00510e 100644
--- a/fp3_sibon.mk
+++ b/fp3_sibon.mk
@@ -13,9 +13,11 @@
 # limitations under the License.
 #
 
+allowed_list += product_manifest.xml Browser2
+
 $(call inherit-product, device/fairphone/fp3-sibon/device.mk)
 
-$(call enforce-product-packages-exist,product_manifest.xml)
+$(call enforce-product-packages-exist,$(allowed_list))
 
 PRODUCT_NAME := fp3_sibon
 PRODUCT_FLAVOR := sibon