Make native_coverage clause work with ClangCoverage

Make uses NATIVE_COVERAGE to enable gcov coverage and CLANG_COVERAGE
to enable clang coverage.  NATIVE_COVERAGE is translated to the Soong
Native_coverage product variable which triggers the native_coverage
clause in Android.bp files.  The clause also needs to be triggered
for CLANG_COVERAGE.

Rename the existing Native_coverage product variable to GcovCoverage,
and regenerate Native_coverage when either GcovCoverage or
ClangCoverage are set.

Also remove NativeLineCoverage, it wasn't doing anything differently
than Native_coverage.

Bug: 159059537
Test: m checkbuild
Change-Id: I215124a9b35a2ad50ad562079d392e3d33da11f4
diff --git a/android/config.go b/android/config.go
index b906108..16f3d73 100644
--- a/android/config.go
+++ b/android/config.go
@@ -406,6 +406,14 @@
 		return Config{}, err
 	}
 
+	if Bool(config.productVariables.GcovCoverage) && Bool(config.productVariables.ClangCoverage) {
+		return Config{}, fmt.Errorf("GcovCoverage and ClangCoverage cannot both be set")
+	}
+
+	config.productVariables.Native_coverage = proptools.BoolPtr(
+		Bool(config.productVariables.GcovCoverage) ||
+			Bool(config.productVariables.ClangCoverage))
+
 	return Config{config}, nil
 }
 
@@ -1057,18 +1065,20 @@
 	return coverage
 }
 
-func (c *config) NativeLineCoverage() bool {
-	return Bool(c.productVariables.NativeLineCoverage)
-}
-
+// Returns true if gcov or clang coverage is enabled.
 func (c *deviceConfig) NativeCoverageEnabled() bool {
-	return Bool(c.config.productVariables.Native_coverage) || Bool(c.config.productVariables.NativeLineCoverage)
+	return Bool(c.config.productVariables.GcovCoverage) ||
+		Bool(c.config.productVariables.ClangCoverage)
 }
 
 func (c *deviceConfig) ClangCoverageEnabled() bool {
 	return Bool(c.config.productVariables.ClangCoverage)
 }
 
+func (c *deviceConfig) GcovCoverageEnabled() bool {
+	return Bool(c.config.productVariables.GcovCoverage)
+}
+
 // NativeCoverageEnabledForPath returns whether (GCOV- or Clang-based) native
 // code coverage is enabled for path. By default, coverage is not enabled for a
 // given path unless it is part of the NativeCoveragePaths product variable (and