Configure ObsoleteLintCustomCheck lint as fatal

Lint raises an issue ObsoleteLintCustomCheck if it detects
incompatibilities between a custom lint check jar and the lint api
itself.

This is a warning by default, but in AOSP it should be fatal.
Any custom checks are expected to run. If they don't, there is risk
of introducing bugs.

ObsoleteLintCustomCheck will now cause build breakage so that it will
be investigated immediately.

Bug: N/A
Test: TH
Change-Id: I3a46c93d5b53ee0e1add7c287af791bd1b41f1c1
diff --git a/java/lint_defaults.txt b/java/lint_defaults.txt
index 519a702..061f4d0 100644
--- a/java/lint_defaults.txt
+++ b/java/lint_defaults.txt
@@ -1,5 +1,10 @@
 # Treat LintError as fatal to catch invocation errors
 --fatal_check LintError
+# ObsoleteLintCustomCheck is a warning by default, but lint ignores the
+# checks from the subject jar if this issue is raised.
+# This should be an error for AOSP. If we create a check, we expect it
+# to run, otherwise we want an error.
+--fatal_check ObsoleteLintCustomCheck
 
 # Checks which do not apply to the platform (implementation
 # in lint assumes that it's running on app code)