Fix #3528: Setup Infrastructure to test using local dev server

[FareesHussain]

Explanation

Fixes #3528
This pr introduces a Testing infrastructure that enables instrumentation tests for downloading explorations and loading images from the local dev server.

This introduces a TestNetworkModule, TestImageParsingModule, and a TestGcsResourceModule.
These modules are used by the OppiaTestApplication and added to a manifest used by the oppia_test android_binary.

oppia_test is similar to the oppia target but it uses the above three modules and a different AndroidManifest

Here I've used two different AndroidManifest in the instrumentation module
one under java directory used for the OppiaTestApplication
and under javatest directory used for InstrumentationTests

Build the test app using:

bazel build //instrumentation:oppia_test

Screenshot

Checklist

• The PR title starts with "Fix #bugnum: ", followed by a short, clear summary of the changes. (If this PR fixes part of an issue, prefix the title with "Fix part of #bugnum: ...".)
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[anandwana001]

Had a quick look here, will look into more detail.

[oppiabot]

Unassigning @anandwana001 since the review is done.

[oppiabot]

Hi @FareesHussain, it looks like some changes were requested on this pull request by @anandwana001. PTAL. Thanks!

[FareesHussain]

@anandwana001 @BenHenning PTAL
Here I'm creating a whole separate application oppia_test which uses AndroidManifest from the instrumentation/src/java
This application uses the Test modules from the instrumentation module and this approach makes it easier to write tests with UiAutomator using uiautomatorviewer while running the app.

Here the AndroidManifest only as two changes compared to the app module.

android:name=".instrumentation.OppiaTestApplication"

and

tools:replace="android:name"

There are some pending kdoc need to be updated, I will update them once the approach is accepted.

[FareesHussain]

@BenHenning can you check how to add a TestFile to get the target
//instrumentation/src/javatests/org/oppia/android/instrumentation/player:InstrumentationTest

if I use

    createBasicTests(
      "InstrumentationTest",
      subpackage = "instrumentation.src.javatests.org.oppia.android.instrumentation.player"
    )

I get the following target
//instrumentation.src.javatests.org.oppia.android.instrumentation.player:InstrumentationTest

[FareesHussain]

@BenHenning can you check how to add a TestFile to get the target
//instrumentation/src/javatests/org/oppia/android/instrumentation/player:InstrumentationTest

if I use

    createBasicTests(
      "InstrumentationTest",
      subpackage = "instrumentation.src.javatests.org.oppia.android.instrumentation.player"
    )

I get the following target
//instrumentation.src.javatests.org.oppia.android.instrumentation.player:InstrumentationTest

It is fixed now, not sure if it is the right way to do that

[BenHenning]

Thanks @FareesHussain. Just had one comment, otherwise the PR LGTM.

[BenHenning]

Thanks @FareesHussain. Given that the past CI run was green & all other comments are resolved, this LGTM. However, please make sure at least https://github.com/oppia/oppia-android/pull/3529/checks?check_run_id=3368705606 is passing before merging since we don't have a required check (yet) for these script tests (which means breakages can be checked in & merged).

[anandwana001]

LGTM, just waiting for all checks to pass and nothing was broken, before merging.

[oppiabot]

Unassigning @anandwana001 since they have already approved the PR.

[BenHenning]

Latest changes LGTM.