conf/sanity: Increase bitbake minimum version requirement

We now need the new bitbake setVarFilter function. There was also some
changes to bb.event.check_for_interrupts() which changed in an
incompatible way.

(From OE-Core rev: 9840877cb7dc9c57c65a2b2740121a8c56b9985b)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/conf/sanity.conf

@@ -3,7 +3,7 @@
 # See sanity.bbclass
 #
 # Expert users can confirm their sanity with "touch conf/sanity.conf"
-BB_MIN_VERSION = "2.15.1"
+BB_MIN_VERSION = "2.15.2"
 
 SANITY_ABIFILE = "${TMPDIR}/abi_version"