Merge changes Ie91d308c,I0d18187b into android-9.0

* changes:
  PL2: Build update_engine_sideload from source
  PL2: Override platform version to 16.1.0

BoardConfig.mk

@@ -59,6 +59,7 @@ TARGET_BOARD_PLATFORM := sdm660
 TARGET_BOARD_PLATFORM_GPU := qcom-adreno508
 
 # Encryption
+PLATFORM_VERSION := 16.1.0
 PLATFORM_SECURITY_PATCH := 2025-12-31
 
 # Partitions