Ensure that HostTest are not empty

- Check that the hostTest test count is 0 we reject the
module.
- Add couple of error_prone rules for harness quality.

Test: make cts javac-check -j76 TARGET_PRODUCT=aosp_arm64
WITH_DEXPREOPT=false RUN_ERROR_PRONE=true
./cts-tradefed run cts-unit-tests
Bug: 36362112
Bug: 37854485

Change-Id: I8fc00b51afff90e966c3c9ed395b6be17eb2486f
diff --git a/error_prone_rules.mk b/error_prone_rules.mk
index c2b0c79..cc28b0d 100644
--- a/error_prone_rules.mk
+++ b/error_prone_rules.mk
@@ -18,6 +18,7 @@
                           -Xep:ConstantField:ERROR \
                           -Xep:FormatString:ERROR \
                           -Xep:GetClassOnClass:ERROR \
+                          -Xep:JUnit3TestNotRun:ERROR \
                           -Xep:JUnitAmbiguousTestClass:ERROR \
                           -Xep:MissingFail:ERROR \
                           -Xep:MissingOverride:ERROR \
@@ -26,5 +27,6 @@
                           -Xep:RemoveUnusedImports:ERROR \
                           -Xep:ReturnValueIgnored:ERROR \
                           -Xep:SelfEquals:ERROR \
-                          -Xep:SizeGreaterThanOrEqualsZero:ERROR
+                          -Xep:SizeGreaterThanOrEqualsZero:ERROR \
+                          -Xep:TryFailThrowable:ERROR