Fix snippets using JPEGs

[glogiotatidis]

A few snippets use JPEGs instead of PNGs. JPEGs do not transparency and those images will not work nicely when users have a non default theme selected.

Snippets using JPEG:

• [x] 10548 - MOCO_Global_2019_P100_Mission_IRL S4 E4 V3_SSB_EN_REL_ESR
• [x] 10547 - MOCO_Global_2019_P100_Mission_IRL S4 E4 V2_SSB_EN_REL_ESR
• [x] 7980 - MOCO_global_2018_f100_week10_campaign_firetv_v1_activity_stream_EN_REL
• [x] 7981 - MOCO_global_2018_f100_week14_campaign_firetv_heyalexa_activity_stream_EN_REL
• [x] 8419 - MOCO_global_2018_f100_week14_campaign_firetv_heyalexa_activity_stream_DE_REL
• [x] 8396 - MOCO_global_2018_f100_week10_campaign_firetv_v1_activity_stream_DE_REL

@mozmeao/lcm-team @stsegovia-moz can you please take of those?

[stevesegovia]

Thanks Giorgos! I'll reach out to the design team and get the PNG/SVG versions of these icons. The bright side is that the IRL snippets are no longer running, but I will still update them.

Thank you! I'll keep you posted when this is done.

[glogiotatidis]

You rock! :metal:

[glogiotatidis]

I checked the snippets listed above and they are all using transparent PNGs now. \o/

Thanks for taking care of this @stsegovia-moz

[stevesegovia]

Thank you Giorgos!