replace deprecated projectDir and buildDir

also fix the resolution of relative output directories: for the
Multiplatform-test it failed because it resolved the path to
":android/my/path"

README.md

@@ -47,7 +47,7 @@ licenseReport {
    
     // Set output directory for the report data.
     // Defaults to ${project.buildDir}/reports/dependency-license.
-    outputDir = "$projectDir/build/licenses"
+    outputDir = project.layout.buildDirectory.dir("licenses").get().asFile.path
 
     // Select projects to examine for dependencies.
     // Defaults to current project and all its subprojects
@@ -84,7 +84,7 @@ licenseReport {
 
     // This is for the allowed-licenses-file in checkLicense Task
     // Accepts File, URL or String path to local or remote file
-    allowedLicensesFile = new File("$projectDir/config/allowed-licenses.json")
+    allowedLicensesFile = project.layout.projectDirectory.file("config/allowed-licenses.json").asFile
 }
 ```
 

src/main/groovy/com/github/jk1/license/LicenseReportExtension.groovy

@@ -44,7 +44,7 @@ class LicenseReportExtension {
 
     LicenseReportExtension(Project project) {
         unionParentPomLicenses = true
-        outputDir = "${project.buildDir}/reports/dependency-license"
+        outputDir = project.layout.buildDirectory.dir("/reports/dependency-license").get().asFile.absolutePath
         projects = [project] + project.subprojects
         renderers = new SimpleHtmlReportRenderer()
         configurations =
@@ -77,7 +77,7 @@ class LicenseReportExtension {
         if (new File(outputDir).isAbsolute()) {
             return outputDir
         } else {
-            return projects.first().absoluteProjectPath(outputDir)
+            return projects.first().layout.projectDirectory.dir(outputDir).asFile.absolutePath
         }
     }