Make dalvik.vm.boot-dex2oat-threads vendor-init-settable.

Bug: 115741899
Test: m selinux_policy
Change-Id: I5d80a1d9bd5500a82ebf282fb02f0db3a0b0a4c1

public/property_contexts

@@ -10,6 +10,7 @@ camera.disable_zsl_mode u:object_r:exported3_default_prop:s0 exact bool
 camera.fifo.disable u:object_r:exported3_default_prop:s0 exact int
 dalvik.vm.appimageformat u:object_r:exported_dalvik_prop:s0 exact string
 dalvik.vm.backgroundgctype u:object_r:exported_dalvik_prop:s0 exact string
+dalvik.vm.boot-dex2oat-threads u:object_r:exported_dalvik_prop:s0 exact int
 dalvik.vm.checkjni u:object_r:exported_dalvik_prop:s0 exact bool
 dalvik.vm.dex2oat-Xms u:object_r:exported_dalvik_prop:s0 exact string
 dalvik.vm.dex2oat-Xmx u:object_r:exported_dalvik_prop:s0 exact string