Add ANDROID_NDK_HOME

Author: Vinh Tran

.bazelci/presubmit.yml

@@ -581,6 +581,8 @@ tasks:
       - "--android_platforms=//:arm64-v8a"
     build_targets:
       - "//:android_app"
+    environment:
+      ANDROID_NDK_HOME: /opt/android-ndk-r25b
   android_examples_macos:
     name: Android Examples
     platform: macos
@@ -591,6 +593,8 @@ tasks:
       - "--android_platforms=//:arm64-v8a"
     build_targets:
       - "//:android_app"
+    environment:
+      ANDROID_NDK_HOME: /opt/android-ndk-r25b
   ios_examples:
     name: iOS Examples
     platform: macos