[Android Build] Enable overriding guava_android_target target 3/9

This CL adds guava_android_target variable to
build/config/android/config.gni in order to enable internal builds to
switch the guava target being used to the internal target.

BUG=1144019

Change-Id: Id93eb3c36256ee786801c7e122e82aefca625f2b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2544045Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Commit-Queue: Peter Kotwicz <pkotwicz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#828253}

build/config/android/config.gni

@@ -132,6 +132,11 @@ if (is_android || is_chromeos ||
     }
   }
 
+  if (!defined(guava_android_target)) {
+    guava_android_target =
+        "//third_party/android_deps:com_google_guava_guava_android_java"
+  }
+
   if (!defined(material_design_target)) {
     material_design_target =
         "//third_party/android_deps:com_google_android_material_material_java"

third_party/android_deps/BUILD.gn

@@ -37,7 +37,7 @@ java_group("espresso_java") {
 }
 
 java_group("guava_android_java") {
-  deps = [ ":com_google_guava_guava_android_java" ]
+  deps = [ guava_android_target ]
 }
 
 java_group("robolectric_all_java") {

third_party/guava/BUILD.gn

@@ -5,5 +5,5 @@
 import("//build/config/android/rules.gni")
 
 java_group("guava_android_java") {
-  deps = [ "//third_party/android_deps:com_google_guava_guava_android_java" ]
+  deps = [ "//third_party/android_deps:guava_android_java" ]
 }