Build: update qcom_utils.mk

Add build macro to determine Android Release

Adding platform sdk version 18 for JB MR2.

Change-Id: I79aa831ddd335bd14bd777506c210acc5d9960f1
inline kernel dtb build

also add sony device filter

Change-Id: Iffeda58c7086f49e76ecafd37941503611346983
build: Prevent some auto-generated variables from being overridden

These variables are used by internal processes for build indexing
and identification, and those processes expect either specific patterns,
or uniqueness.
So prevent accidental overriding of these by device configurations:
BUILD_DISPLAY_ID, BUILD_NUMBER, PLATFORM_VERSION, PLATFORM_SDK_VERSION,
PLATFORM_VERSION_CODENAME, BUILD_VERSION_TAGS

Change-Id: I06252f2687a5e5fd97ee21a98f26c739fd0ef6e4
Add a unique build number to every build

SDK-readable via android.os.Build.INCREMENTAL

Change-Id: If9885adebe12a56b2b2e353285721be695bc411b

Conflicts:
	envsetup.sh
Fix exporting the unique build identifier

Change-Id: Ie58e981b7e83a4351d137dfd8995dce7d365d950

Conflicts:
	envsetup.sh