IMA: Support midrolls in live streams

We are testing Live Stream with Midrolls and it seems Exoplayer gets stuck on an invalid state when Ads Uri Requests contains Midrolls.

As mentioned here (https://github.com/google/ExoPlayer/issues/5005#issuecomment-440601762) it seems Midrolls are not supported by Exoplayer IMA extension.
Could you confirm it or if there is any plan to support it?

To reproduce it, use IMA Exo Demo and Ads Request with Midroll:
Content: http://livesim.dashif.org/livesim/testpic_2s/Manifest.mpd
Ads: https://pubads.g.doubleclick.net/gampad/ads?sz=640x480&iu=/124319096/external/ad_rule_samples&ciu_szs=300x250&ad_rule=1&impl=s&gdfp_req=1&env=vp&output=vmap&unviewed_position_start=1&cust_params=deployment%3Ddevsite%26sample_ar%3Dpremidpost&cmsid=496&vid=short_onecue&correlator=