Hook up LeakCanary to ChromePublic.apk (behind a GN arg)

chrome/android/chrome_public_apk_tmpl.gni

Index: chrome/android/chrome_public_apk_tmpl.gni
diff --git a/chrome/android/chrome_public_apk_tmpl.gni b/chrome/android/chrome_public_apk_tmpl.gni
index 57974ef42b26ac3131025d37cd0bb4fe6f9535d8..39810f7fe50551181e464cf9058178c13032528e 100644
--- a/chrome/android/chrome_public_apk_tmpl.gni
+++ b/chrome/android/chrome_public_apk_tmpl.gni
@@ -3,6 +3,9 @@
 # found in the LICENSE file.
 
 import("//build/config/android/rules.gni")
+import("//chrome/common/features.gni")
+import("//third_party/leakcanary/config.gni")
+import("channel.gni")
 
 declare_args() {
   # Whether chrome_public_apk should use the crazy linker.
@@ -15,6 +18,16 @@ declare_args() {
   chrome_public_apk_load_library_from_apk = true
 }
 
+default_chrome_public_jinja_variables = [
+  "channel=$android_channel",
+  "enable_leakcanary=$enable_leakcanary",
+]
+if (enable_configuration_policy) {
+  default_chrome_public_jinja_variables += [ "configuration_policy=1" ]
+} else {
+  default_chrome_public_jinja_variables += [ "configuration_policy=0" ]
+}
+
 # GYP: //chrome/android/chrome_apk.gypi
 template("chrome_public_apk_tmpl") {
   android_apk(target_name) {