Dedup generating xml file for java_sdk_library

Permission XML file for java_sdk_library is generated by
java_sdk_library itself now.

And, build rule is switched to android.WriteFile since "echo -e" is
not supported from build server. (-e is printed to output)

Bug: 145474221
Test: m com.android.cronet and check its permissions xml file
     also, m org.chromium.net.cronet.xml (created dynamically)
Change-Id: Iffb119151c49bc4fe6c4386fa267cca193f37dbc

apex/apex.go

@@ -1024,12 +1024,12 @@ func (a *apexBundle) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 					}
 					filesInfo = append(filesInfo, af)
 
-					pf := sdkLib.PermissionFile()
-					if pf == nil {
+					pf, _ := sdkLib.OutputFiles(".xml")
+					if len(pf) != 1 {
 						ctx.PropertyErrorf("java_libs", "%q failed to generate permission XML", depName)
 						return false
 					}
-					filesInfo = append(filesInfo, newApexFile(ctx, pf, pf.Base(), "etc/permissions", etc, nil))
+					filesInfo = append(filesInfo, newApexFile(ctx, pf[0], pf[0].Base(), "etc/permissions", etc, nil))
 					return true // track transitive dependencies
 				} else {
 					ctx.PropertyErrorf("java_libs", "%q of type %q is not supported", depName, ctx.OtherModuleType(child))

apex/apex_test.go

@@ -3288,8 +3288,8 @@ func TestJavaSDKLibrary(t *testing.T) {
 		"etc/permissions/foo.xml",
 	})
 	// Permission XML should point to the activated path of impl jar of java_sdk_library
-	genXMLCommand := ctx.ModuleForTests("foo", "android_common_myapex").Output("foo.xml").RuleParams.Command
-	ensureContains(t, genXMLCommand, `<library name="foo" file="/apex/myapex/javalib/foo.jar"`)
+	xml := ctx.ModuleForTests("foo", "android_common_myapex").Output("foo.xml")
+	ensureContains(t, xml.Args["content"], `<library name="foo" file="/apex/myapex/javalib/foo.jar"`)
 }
 
 func TestRejectNonInstallableJavaLibrary(t *testing.T) {