Re-plumb fuzz corpora.

Re-plumb the fuzz corpora through an intermediates directory.
Previously, due to the way that LOCAL_TEST_DATA is implemented, we would
break when corpora were included:
 a) outside of a corpus/ directory, or
 b) not directly under the module directory (i.e. my_module/subdir/corpus)

Corpora are now written into an intermediates directory so that they
play nice with LOCAL_TEST_DATA, because unfortunately the key-value pair
required there is not as simple as source:destination.

Test: m example_fuzzer && ls \
$ANDROID_PRODUCT_OUT/data/fuzz/arm64/example_fuzzer/corpus
Bug: N/A

Change-Id: I5888b06ed349781c6712f1ae77cc3582283a9552

cc/androidmk.go

@@ -308,15 +308,13 @@ func (fuzz *fuzzBinary) AndroidMk(ctx AndroidMkContext, ret *android.AndroidMkDa
 
 	var fuzzFiles []string
 	for _, d := range fuzz.corpus {
-		rel := d.Rel()
-		path := d.String()
-		path = strings.TrimSuffix(path, rel)
-		fuzzFiles = append(fuzzFiles, path+":corpus/"+d.Base())
+		fuzzFiles = append(fuzzFiles,
+			filepath.Dir(fuzz.corpusIntermediateDir.String())+":corpus/"+d.Base())
 	}
 
 	if fuzz.dictionary != nil {
-		path := strings.TrimSuffix(fuzz.dictionary.String(), fuzz.dictionary.Rel())
-		fuzzFiles = append(fuzzFiles, path+":"+fuzz.dictionary.Base())
+		fuzzFiles = append(fuzzFiles,
+			filepath.Dir(fuzz.dictionary.String())+":"+fuzz.dictionary.Base())
 	}
 
 	if len(fuzzFiles) > 0 {