beckham: update product shipping api level

* beckham shipped with oreo-mr1 (android 8.1.0)

Change-Id: I4b5da79e22acca3846b04feaa168bfe3e9a73cab
Signed-off-by: Joshua Blanchard <joshua.lee.bbg@gmail.com>

BoardConfig.mk

@@ -44,7 +44,7 @@ TARGET_HAS_NO_WLAN_STATS := true
 ENABLE_VENDOR_RIL_SERVICE := false
 
 # Treble
-PRODUCT_SHIPPING_API_LEVEL := 26
+PRODUCT_SHIPPING_API_LEVEL := 27
 
 # inherit from the proprietary version
 -include vendor/motorola/beckham/BoardConfigVendor.mk