"/instl: 1" flag is sending even in case of video banner

[takenorim]

Describe the bug
Even in case of Video Banner use-case (which is NOT an interstitial ads), we found the OpenRTB object /instl: 1 is sending from the Prebid Android SDK to a Prebid Server. I believe this flag should not sending in case of video banner use-case. Actually, many of bidders does not expect /instl: 1 if this impression is not an interstitial ads.

Can you clarify whether this Android SDK behavior is something expected or a bug?

To Reproduce
I can confirm this behavior with Prebid Demo app (e.g. GamOriginalApiVideoBannerActivity). This is relevant Logcat messages.

2024-06-03 13:28:59.660 32272-32483 PrebidBaseNetworkTask   org.prebid.mobile.prebidkotlindemo   D  url: https://prebid-server-test-j.prebid.org/openrtb2/auction

2024-06-03 13:28:59.661 32272-32483 PrebidBaseNetworkTask   org.prebid.mobile.prebidkotlindemo   D  queryParams: {"imp":[{"id":"ffc2104e-5367-431a-ac7d-24e5e6680f80","instl":1,"clickbrowser":0,"video":{"mimes":["video\/x-flv","video\/mp4"],"minduration":5,"maxduration":30,"protocols":[2],"minbitrate":300,"maxbitrate":1500,"playbackmethod":[1],"delivery":[3],"api":[1,2]},"ext":{"prebid":{"storedrequest":{"id":"prebid-demo-video-outstream-original-api"}}}}],"id":"ffc2104e-5367-431a-ac7d-24e5e6680f80","app":{"name":"Prebid Kotlin Demo","bundle":"org.prebid.mobile.prebidkotlindemo","ver":"1.0.0","publisher":{"id":"0689a263-318d-448b-a3d4-b02e8a709d9d"},"ext":{"prebid":{"source":"prebid-mobile","version":"2.2.0"}}},"device":{"ua":"Mozilla\/5.0 (Linux; Android 14; sdk_gphone64_arm64 Build\/UE1A.230829.036.A1; wv) AppleWebKit\/537.36 (KHTML, like Gecko) Version\/4.0 Chrome\/113.0.5672.136 Mobile Safari\/537.36","lmt":0,"devicetype":4,"make":"Google","model":"sdk_gphone64_arm64","os":"Android","osv":"14","language":"en","carrier":"T-Mobile","mccmnc":"310-260","ifa":"1336c7ac-2b2e-490c-9cae-10ca1ad1abe1","h":2220,"w":1080,"connectiontype":2,"pxratio":2.75},"regs":{"ext":{"gdpr":1}},"user":{},"source":{"tid":"ffc2104e-5367-431a-ac7d-24e5e6680f80"},"ext":{"prebid":{"storedrequest":{"id":"0689a263-318d-448b-a3d4-b02e8a709d9d"},"cache":{"bids":{},"vastxml":{}},"targeting":{}}}}

Expected behavior
/instl: 1 flag is not sending for Non Interstitial ads

Additional context
We believe this is relevant code codes how the Prebid SDK add /instl: 1.

• prebid-mobile-android/PrebidMobile/PrebidMobile-core/src/main/java/org/prebid/mobile/rendering/networking/parameters/BasicParameterBuilder.java

  Lines 372 to 374 in 6f1da30

  	boolean isInterstitial = adConfiguration.isAdType(AdFormat.VAST) || adConfiguration.isAdType(AdFormat.INTERSTITIAL);
  	//Send 1 for interstitial/interstitial video and 0 for banners
  	imp.instl = isInterstitial ? 1 : 0;

        boolean isInterstitial = adConfiguration.isAdType(AdFormat.VAST) || adConfiguration.isAdType(AdFormat.INTERSTITIAL);
        //Send 1 for interstitial/interstitial video and 0 for banners
        imp.instl = isInterstitial ? 1 : 0;

• prebid-mobile-android/PrebidMobile/PrebidMobile-core/src/main/java/org/prebid/mobile/api/data/AdFormat.java

  Lines 30 to 31 in 6f1da30

  	if (format == AdUnitFormat.VIDEO) {
  	result.add(AdFormat.VAST);

            if (format == AdUnitFormat.VIDEO) {
                result.add(AdFormat.VAST);

A similar condition in the iOS code checks only for the interstitial ad format, and not VAST. As a result, this issue doesn't happen on iOS.

[ValentinPostindustria]

During the investigation, we discovered that some constructors for Interstitial and Rewarded ad units do not have AdFormat.INTERSTITIAL. So even after applying the fix, they still have instl 0.