Host gtests: Use the apex boot image instead of core.art.

Closely mirror the behaviour of target tests.

Test: m test-art-host-gtest
Bug: 147817558
Change-Id: If9a1d34cef022fa93c9c09c8f31adc26ac71afdc
diff --git a/tools/build_linux_bionic_tests.sh b/tools/build_linux_bionic_tests.sh
index 76dabd4..c834dd5 100755
--- a/tools/build_linux_bionic_tests.sh
+++ b/tools/build_linux_bionic_tests.sh
@@ -82,7 +82,7 @@
   $soong_out/bin/hprof-conv
   $soong_out/bin/signal_dumper
   $soong_out/lib64/libclang_rt.ubsan_standalone-x86_64-android.so
-  $(find $host_out/apex -type f | sed "s:$host_out:$soong_out:g")
+  $(find $host_out/apex/com.android.art.host.zipapex -type f | sed "s:$host_out:$soong_out:g")
   $(find $host_out/lib64 -type f | sed "s:$host_out:$soong_out:g")
   $(find $host_out/nativetest64 -type f | sed "s:$host_out:$soong_out:g"))