Install prebuilt_etc modules to out/soong

prebuilt_etc* modules emit build rules to install their output to
out/soong. This is required for the cvd_host_package module to gather
installed files (not built files) of prebuilt_etc* modules.

Bug: 168086242
Test: m

Change-Id: I065640c7e6f188b0c19e70f081e82bdc30d7e752

etc/prebuilt_etc.go

@@ -214,6 +214,13 @@ func (p *PrebuiltEtc) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 		Output: p.outputFilePath,
 		Input:  p.sourceFilePath,
 	})
+
+	if p.Installable() {
+		installPath := ctx.InstallFile(p.installDirPath, p.outputFilePath.Base(), p.outputFilePath)
+		for _, sl := range p.properties.Symlinks {
+			ctx.InstallSymlink(p.installDirPath, sl, installPath)
+		}
+	}
 }
 
 func (p *PrebuiltEtc) AndroidMkEntries() []android.AndroidMkEntries {