Add WITH_HWCRYPTO_UNITTEST=1 in test builds

The WITH_HWCRYPTO_UNITTEST define is required to build hwkey with test
keyslots and to enable testing of this functionality. This define was
not previously set anywhere. Enable hwcrypto unittests in generic-arm
test builds.

Bug: 186166757
Change-Id: I87c39fbb115c97b058fbdc35fd0b63830e91fdd2
diff --git a/project/ b/project/
index 077fc10..3301c22 100644
--- a/project/
+++ b/project/
@@ -23,4 +23,7 @@
 # and intentionally attempts to induce crashes for bad assumptions.
 GLOBAL_SHARED_COMPILEFLAGS += -ftrivial-auto-var-init=pattern
+# Enable hwcrypto unittest keyslots and tests
 TEST_BUILD := true