Support path exclusion for native coverage.

Specify list of paths to exclude from coverage instrumentation.

Test: make NATIVE_COVERAGE=true COVERAGE_PATHS=hardware/interfaces
COVERAGE_EXCLUDE_PATHS=hardware/interfaces/graphics
Bug: 35769817

Change-Id: I3bf10e5e5697d140d6cff73d000768b00aa28ca4
diff --git a/android/variable.go b/android/variable.go
index 68fa7cd..c5b957b 100644
--- a/android/variable.go
+++ b/android/variable.go
@@ -121,8 +121,9 @@
 	ClangTidy  *bool   `json:",omitempty"`
 	TidyChecks *string `json:",omitempty"`
 
-	NativeCoverage *bool     `json:",omitempty"`
-	CoveragePaths  *[]string `json:",omitempty"`
+	NativeCoverage       *bool     `json:",omitempty"`
+	CoveragePaths        *[]string `json:",omitempty"`
+	CoverageExcludePaths *[]string `json:",omitempty"`
 
 	DevicePrefer32BitExecutables *bool `json:",omitempty"`
 	HostPrefer32BitExecutables   *bool `json:",omitempty"`