Add apex name to description

Otherwise we see multiple concurrent builds of different actions with
the same description:

    0:09 //external/fmtlib:fmtlib clang++ src/format.cc
    0:09 //external/fmtlib:fmtlib clang++ src/format.cc
    0:09 //external/fmtlib:fmtlib clang++ src/format.cc
    0:09 //external/fmtlib:fmtlib clang++ src/format.cc
    0:09 //external/fmtlib:fmtlib clang++ src/format.cc

Is now:

    0:09 //external/fmtlib:fmtlib clang++ src/format.cc
    0:09 //external/fmtlib:fmtlib clang++ src/format.cc [com.android.resolv]
    0:09 //external/fmtlib:fmtlib clang++ src/format.cc [com.android.adbd]
    0:09 //external/fmtlib:fmtlib clang++ src/format.cc [com.android.art.debug]
    0:09 //external/fmtlib:fmtlib clang++ src/format.cc [com.android.media]

Test: m  <watch output>
Change-Id: Ib8fccc144e8fe5fc33cafe8536538b892bd42765
diff --git a/android/module.go b/android/module.go
index 5e56c4f..fd3fec3 100644
--- a/android/module.go
+++ b/android/module.go
@@ -1112,6 +1112,9 @@
 	if !ctx.PrimaryArch() {
 		suffix = append(suffix, ctx.Arch().ArchType.String())
 	}
+	if apex, ok := m.module.(ApexModule); ok && !apex.IsForPlatform() {
+		suffix = append(suffix, apex.ApexName())
+	}
 
 	ctx.Variable(pctx, "moduleDesc", desc)