Disabled publishJavadoc by default for tests

It should be enabled explicitly when being tested anyhow, and causes issues otherwise. Instead of disabling it for the tests that don't need it- this is much quicker and easier to manager.

Author: daymxn

buildSrc/src/test/kotlin/com/google/firebase/gradle/plugins/publishing.kt

@@ -29,6 +29,7 @@ data class Project(
     val externalDependencies: Set<Artifact> = setOf(),
     val releaseWith: Project? = null,
     val customizePom: String? = null,
+    val publishJavadoc: Boolean = false,
     val libraryType: LibraryType = LibraryType.ANDROID
 ) {
     fun generateBuildFile(): String {
@@ -42,6 +43,7 @@ data class Project(
             firebaseLibrary {
                 ${if (releaseWith != null) "releaseWith project(':${releaseWith.name}')" else ""}
                 ${if (customizePom != null) "customizePom {$customizePom}" else ""}
+                ${"publishJavadoc = $publishJavadoc"}
             }
             ${if (libraryType == LibraryType.ANDROID) "android.compileSdkVersion = 26" else ""}