Generalize parent repository logic.

This commit generalizes the path to the parent repository which contains
the m2repository for the smoke tests.

Author: allisonbm92

smoke-tests/build.gradle

@@ -77,17 +77,6 @@ android {
   }
 }
 
-repositories {
-  google()
-  jcenter()
-
-  // This is necessary for Bill of Materials injection. This repository is created by running the
-  // `publishAllToBuildDir` task on the main firebase-android-sdk project.
-  maven {
-    url "../build/m2repository/"
-  }
-}
-
 apply from: "configure.gradle"
 
 dependencies {

smoke-tests/configure.gradle

@@ -30,4 +30,23 @@ def configurePlatform() {
   }
 }
 
+def configureRepositories() {
+  def m2repo = "../build/m2repository/"
+  if (project.hasProperty("m2repo")) {
+    m2repo = project.getProperty("m2repo")
+  }
+
+  project.repositories {
+    // This is necessary for Bill of Materials injection. This repository is created by running the
+    // `assembleAllForSmokeTests` task on the main firebase-android-sdk project.
+    maven {
+      url m2repo
+    }
+
+    google()
+    jcenter()
+  }
+}
+
+configureRepositories()
 configurePlatform()