ndk: Set TARGET_RELEASE in NDK ABI dump script

TARGET_RELEASE variable is required to have correct platform variables
set up before NDK build. There are different possible values for this
variable:

* "next" - the platform will be built like current development version
  is now a release version. For ABI monitoring this means that
  previously codenamed version like "UpsideDownCake" is now a numbered
  version like "34".
* "trunk_staging" - in-development version with some features being
  staged for subsequent releses.

The main goal of NDK ABI monitoring is to catch ABI breakages as soon as
possible, which means that "trunk_staging" is the best candidate for
dumping and diffing NDK ABI.

Test: development/tools/ndk/update_ndk_abi.sh
Bug: 156513478
Change-Id: Ie07c865e6415084a0268a566842d0b46971c7a2d
1 file changed