List baseline_filename on modules that are implititly using it

lintable modules currently pick up files named "lint-baseline.xml" to use as the
lint baseline implicitly. This is confusing because you could end up using the
baseline files in more modules than intended. Lint also has a feature where it
requests you remove unnecessary findings from the baseline file, so something
could be necessary for one module, but unnecessary for another that accidentally
picked up the baseline.

We're removing the implicit detection of the baseline file, which requires
all modules using it to list the baseline file explicitly.

Bug: 272769514
Test: Presubmits
Change-Id: I34c7d73667d2868555d4d29f80f17f07900c5337
diff --git a/Android.bp b/Android.bp
index 36923ab..a1baa30 100644
--- a/Android.bp
+++ b/Android.bp
@@ -57,4 +57,7 @@
 
     sdk_version: "system_current",
     min_sdk_version: "21",
+    lint: {
+        baseline_filename: "lint-baseline.xml",
+    },
 }