Collect JNI coverage data only for first target.

Modules with compile_multilib property set to "both" cause builds to
fail due to duplicate Make recipes. Fix it by outputting reports only
for the first target for now.

(This is a cherry-pick change.)

Bug: 153461674
Test: Built cts with the coverage flags set.
Change-Id: Ibb8da6e9c112a857695cd7095a62c910cddfbb94
Merged-In: Ibb8da6e9c112a857695cd7095a62c910cddfbb94
diff --git a/java/app.go b/java/app.go
index 6a0aa8f..c9ae3e7 100755
--- a/java/app.go
+++ b/java/app.go
@@ -392,7 +392,18 @@
 			TransformJniLibsToJar(ctx, jniJarFile, jniLibs, a.useEmbeddedNativeLibs(ctx))
 			for _, jni := range jniLibs {
 				if jni.coverageFile.Valid() {
-					a.jniCoverageOutputs = append(a.jniCoverageOutputs, jni.coverageFile.Path())
+					// Only collect coverage for the first target arch if this is a multilib target.
+					// TODO(jungjw): Ideally, we want to collect both reports, but that would cause coverage
+					// data file path collisions since the current coverage file path format doesn't contain
+					// arch-related strings. This is fine for now though; the code coverage team doesn't use
+					// multi-arch targets such as test_suite_* for coverage collections yet.
+					//
+					// Work with the team to come up with a new format that handles multilib modules properly
+					// and change this.
+					if len(ctx.Config().Targets[android.Android]) == 1 ||
+						ctx.Config().Targets[android.Android][0].Arch.ArchType == jni.target.Arch.ArchType {
+						a.jniCoverageOutputs = append(a.jniCoverageOutputs, jni.coverageFile.Path())
+					}
 				}
 			}
 		} else {