Prevent kotlinc from reading /tmp/build.txt

Pass -Didea.plugins.compatible.build=999.SNAPSHOT to kotlinc and kapt
to prevent it from reading /tmp/build.txt and failing with an obscure
exception:
exception: java.lang.ExceptionInInitializerError
	at com.intellij.openapi.util.BuildNumber.currentVersion(BuildNumber.java:297)
...

Bug: 222162908
Test: m metalava with /tmp/build.txt present
Change-Id: I5faced4a2e94561ce3aa37bfaacf5bd7d988a4f0