Build: update qcom_utils.mk

Add build macro to determine Android Release

Adding platform sdk version 18 for JB MR2.

Change-Id: I79aa831ddd335bd14bd777506c210acc5d9960f1
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
qcom_utils: Add qsd8k to qcom platforms

PS2: fix typo

Change-Id: Id85569d1dd7be2f4c0620827da6d89e63b658aa9