support installing platforms with full version

Google sometimes releases bugfix versions of platforms;android-23 packages, but provides no way to install the specific versions. That version sometimes gets put into the manifest:

<manifest·​android:​versionCode="5" ​android:​versionName="1.​2" ​package="com.​anysoftkeyboard.​languagepack.​neo" platformBuildVersionC​ode="23" ​platformBuildVersionN​ame="6.​0-​2166767" 

https://verification.f-droid.org/com.anysoftkeyboard.languagepack.neo_5.apk.diffoscope.html

It shouldn't be hard, since the value is in the build.prop file under ro.build.version.incremental, which is stored in checksums.json.

~ $ jq '.["https://dl.google.com/android/repository/android-23_r01.zip"]' ~/.cache/sdkmanager/checksums.json

[
  {
    "build.prop": "\n# begin build properties\n# autogenerated by buildinfo.sh\nro.build.id=MRA44C\nro.build.display.id=sdk_phone_armv7-eng 6.0 MRA44C 2166767 test-keys\nro.build.version.incremental=2166767\nro.build.version.sdk=23\nro.build.version.preview_sdk=0\nro.build.version.codename=REL\nro.build.version.all_codenames=REL\nro.build.version.release=6.0\nro.build.version.security_patch=\nro.build.version.base_os=\nro.build.date=Thu Aug 13 23:46:41 UTC 2015\nro.build.date.utc=1439509601\nro.build.type=eng\nro.build.tags=test-keys\nro.build.flavor=sdk_phone_armv7-eng\nro.product.model=sdk_phone_armv7\nro.product.name=sdk_phone_armv7\nro.product.board=\n# ro.product.cpu.abi and ro.product.cpu.abi2 are obsolete,\n# use ro.product.cpu.abilist instead.\nro.product.cpu.abi=armeabi-v7a\nro.product.cpu.abi2=armeabi\nro.product.cpu.abilist=armeabi-v7a,armeabi\nro.product.cpu.abilist32=armeabi-v7a,armeabi\nro.product.cpu.abilist64=\nro.product.locale=en-US\nro.wifi.channels=\nro.board.platform=\n# ro.build.product is obsolete; use ro.product.device\n# Do not try to parse description, fingerprint, or thumbprint\nro.build.description=sdk_phone_armv7-eng 6.0 MRA44C 2166767 test-keys\nro.build.fingerprint=generic/sdk_phone_armv7/generic:6.0/MRA44C/2166767:eng/test-keys\nro.build.characteristics=default\n# end build properties\n#\n# from build/target/board/generic/system.prop\n#\n#\n# system.prop for generic sdk\n#\n\nrild.libpath=/system/lib/libreference-ril.so\nrild.libargs=-d /dev/ttyS0\n\n#\n# ADDITIONAL_BUILD_PROPERTIES\n#\nro.config.notification_sound=OnTheHunt.ogg\nro.config.alarm_alert=Alarm_Classic.ogg\npersist.sys.dalvik.vm.lib.2=libart\ndalvik.vm.isa.arm.variant=generic\ndalvik.vm.isa.arm.features=default\nro.kernel.android.checkjni=1\ndalvik.vm.lockprof.threshold=500\ndalvik.vm.usejit=true\nxmpp.auto-presence=true\nro.config.nocheckin=yes\nnet.bt.name=Android\ndalvik.vm.stack-trace-file=/data/anr/traces.txt\nro.build.user=generic\nro.build.host=generic\nro.product.brand=generic\nro.product.manufacturer=generic\nro.product.device=generic\nro.build.product=generic\n",
    "sdk.properties": "# SDK properties\n# This file is copied in the root folder of each platform component.\n# If it used by various tools to figure out what the platform can do.\nsdk.ant.templates.revision=1\nsdk.skin.default=WVGA800",
    "sha1": "cbccca8d3127e894845556ce999b28281de541bd",
    "sha256": "16e828bec35521f5529c998a6d312aaa6155cd4aabb5507d9eb2d4b3c9a1aff0",
    "sha512": "2a7ed9d6dac60de755f232e3ac4e76705c1bdfa328dae4b96c750c66a16ebded2255b2596f04f73eba04a9e43c8626d65380e5a734d1288105b96eda5dd9d731",
    "source.properties": "Pkg.Desc=Android SDK Platform 6.0\nPkg.UserSrc=false\nPlatform.Version=6.0\nPlatform.CodeName=\nPkg.Revision=1\nAndroidVersion.ApiLevel=23\nLayoutlib.Api=15\nLayoutlib.Revision=1\nPlatform.MinToolsRev=22\n"
  }
]