compose: Adjust compose box for mobile at 374px vs 370px.
compose: Adjust compose box for mobile at 374px vs 370px.

Since the change in breakpoint is minor no regression is seen.

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