compose: Increase opacity of icons.
compose: Increase opacity of icons.

The icons at the bottom were previously too low-contrast, so bump the
opacity up to 0.7 from 0.4.

rht/zulip,kou/zulip,eeshangarg/zulip,kou/zulip,kou/zulip,eeshangarg/zulip,eeshangarg/zulip,rht/zulip,punchagan/zulip,andersk/zulip,zulip/zulip,zulip/zulip,punchagan/zulip,zulip/zulip,andersk/zulip,andersk/zulip,kou/zulip,eeshangarg/zulip,rht/zulip,zulip/zulip,hackerkid/zulip,hackerkid/zulip,hackerkid/zulip,punchagan/zulip,punchagan/zulip,rht/zulip,eeshangarg/zulip,andersk/zulip,zulip/zulip,andersk/zulip,hackerkid/zulip,punchagan/zulip,hackerkid/zulip,eeshangarg/zulip,kou/zulip,kou/zulip,zulip/zulip,hackerkid/zulip,hackerkid/zulip,punchagan/zulip,kou/zulip,eeshangarg/zulip,punchagan/zulip,andersk/zulip,andersk/zulip,rht/zulip,rht/zulip,rht/zulip,zulip/zulip