Build native coverage variant of APEXes when needed

When the native coverage is enabled, APEXes (and files there) are built
for native coverage as well.

Bug: 138952487
Test: make -j NATIVE_COVERAGE=true COVERAGE_PATHS='*' com.android.resolv
find out -name "*.gcno" | grep DnsResolver shows files

Test: libnetd_resolv.zip is found under
$(TARGET_OUT)/apex/com.android.resolv/lib directory

Change-Id: I97bcee9bf8ffc0dc71453abbdb613ed56ea2cdb4
diff --git a/cc/cc.go b/cc/cc.go
index 2bde2d3..c130a07 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -327,6 +327,7 @@
 	unstrippedOutputFilePath() android.Path
 
 	nativeCoverage() bool
+	coverageOutputFilePath() android.OptionalPath
 }
 
 type installer interface {
@@ -461,6 +462,13 @@
 	return nil
 }
 
+func (c *Module) CoverageOutputFile() android.OptionalPath {
+	if c.linker != nil {
+		return c.linker.coverageOutputFilePath()
+	}
+	return android.OptionalPath{}
+}
+
 func (c *Module) RelativeInstallPath() string {
 	if c.installer != nil {
 		return c.installer.relativeInstallPath()