soong: allow overriding header files

Includes:

  Author: Jan Altensen <info@stricted.net>
  Date:   Sat Aug 7 19:41:59 2021 +0200

    soong: move header override to compiler.go

     * library.go only covers libraries

    Change-Id: I3374999d6b364dd1bbc2060996964ee7b04493e7

Change-Id: Ia9d2210605c5927b529fbe9485b0e5abd079f487

android/config.go

@@ -1448,6 +1448,10 @@ func (c *deviceConfig) DeviceKernelHeaderDirs() []string {
 	return c.config.productVariables.DeviceKernelHeaders
 }
 
+func (c *deviceConfig) TargetSpecificHeaderPath() string {
+	return String(c.config.productVariables.TargetSpecificHeaderPath)
+}
+
 // JavaCoverageEnabledForPath returns whether Java code coverage is enabled for
 // path. Coverage is enabled by default when the product variable
 // JavaCoveragePaths is empty. If JavaCoveragePaths is not empty, coverage is

android/variable.go

@@ -367,6 +367,8 @@ type ProductVariables struct {
 
 	DeviceKernelHeaders []string `json:",omitempty"`
 
+	TargetSpecificHeaderPath *string `json:",omitempty"`
+
 	ExtraVndkVersions []string `json:",omitempty"`
 
 	NamespacesToExport []string `json:",omitempty"`