Making dokka_version propagate correctly into built artifacts when it changes

Bug: 149482984
Test: cd external/dokka \
      && grep dokka_version gradle.properties \
      && echo "see dokka_version=0.9.17-g007" \
      && ./gradlew publish \
      && sed -i 's/007/008/' gradle.properties \
      && ./gradlew publish \
      && cd build/dist-maven/org/jetbrains/dokka/dokka-android-gradle-plugin/0.9.17-g008 \
      && unzip dokka-android-gradle-plugin-0.9.17-g008.jar -d dokka-android-gradle-plugin-0.9.17-g008.jar_unzipped \
      && grep dokka-version dokka-android-gradle-plugin-0.9.17-g008.jar_unzipped/META-INF/gradle-plugins/org.jetbrains.dokka-android.properties \
      # and see that this says 'dokka-version=0.9.17-g008' as expected

Change-Id: Ic134e764e066a6664caec07ccf1c3905d1a2ebcd
diff --git a/runners/android-gradle-plugin/build.gradle b/runners/android-gradle-plugin/build.gradle
index 72d1be9..22403dc 100644
--- a/runners/android-gradle-plugin/build.gradle
+++ b/runners/android-gradle-plugin/build.gradle
@@ -38,6 +38,7 @@
 }
 
 processResources {
+    inputs.property("dokka_version", dokka_version)
     eachFile {
         if (it.name == "org.jetbrains.dokka-android.properties") {
             it.filter { line ->
@@ -98,4 +99,4 @@
         groupId = "org.jetbrains.dokka"
         artifactId = "dokka-android-gradle-plugin"
     }
-}
\ No newline at end of file
+}
diff --git a/runners/gradle-plugin/build.gradle b/runners/gradle-plugin/build.gradle
index 661d432..a067080 100644
--- a/runners/gradle-plugin/build.gradle
+++ b/runners/gradle-plugin/build.gradle
@@ -35,6 +35,7 @@
 }
 
 processResources {
+    inputs.property("dokka_version", dokka_version)
     eachFile {
         if (it.name == "org.jetbrains.dokka.properties") {
             it.filter { line ->
@@ -96,4 +97,4 @@
         groupId = "org.jetbrains.dokka"
         artifactId = "dokka-gradle-plugin"
     }
-}
\ No newline at end of file
+}
diff --git a/runners/maven-plugin/build.gradle b/runners/maven-plugin/build.gradle
index 79a8c22..acd3415 100644
--- a/runners/maven-plugin/build.gradle
+++ b/runners/maven-plugin/build.gradle
@@ -33,6 +33,9 @@
 
 task generatePom() {
     inputs.file(new File(projectDir, "pom.tpl.xml"))
+    inputs.property("dokka_version", dokka_version)
+    inputs.property("maven_version", maven_version)
+    inputs.property("maven_plugin_tools_version", maven_plugin_tools_version)
     outputs.file(new File(buildDir, "pom.xml"))
     doLast {
         final pomTemplate = new File(projectDir, "pom.tpl.xml")