[styles] Create a new JSS instance with injectFirst

[oliviertassinari]

Closes #15557

It seems to work correctly: https://codesandbox.io/s/xv688v1p0z.

[mui-pr-bot]

@material-ui/core: parsed: +0.01% , gzip: -0.15% 😍
@material-ui/lab: parsed: +0.03% , gzip: -0.24% 😍

Details of bundle changes.

Comparing: e36d33a...8572b1d

bundle	parsed diff	gzip diff	prev parsed	current parsed	prev gzip	current gzip
@material-ui/core	+0.01% 🔺	-0.15%	310,611	310,648	84,595	84,465
@material-ui/core/Paper	+0.05% 🔺	+0.01% 🔺	67,705	67,742	20,130	20,132
@material-ui/core/Paper.esm	+0.06% 🔺	-0.54%	61,003	61,040	19,038	18,935
@material-ui/core/Popper	0.00%	-0.02%	28,590	28,590	10,290	10,288
@material-ui/core/Textarea	0.00%	-0.13%	5,513	5,513	2,381	2,378
@material-ui/core/TrapFocus	0.00%	0.00%	3,780	3,780	1,577	1,577
@material-ui/core/styles/createMuiTheme	0.00%	+0.02% 🔺	15,943	15,943	5,777	5,778
@material-ui/core/useMediaQuery	0.00%	-0.41%	2,106	2,106	977	973
@material-ui/lab	+0.03% 🔺	-0.24%	139,644	139,681	42,535	42,431
@material-ui/styles	+0.07% 🔺	+0.03% 🔺	51,234	51,271	15,156	15,161
@material-ui/system	0.00%	-0.05%	11,765	11,765	3,924	3,922
Button	+0.04% 🔺	-0.49%	85,318	85,355	25,686	25,561
Modal	0.00%	0.00%	20,366	20,366	6,692	6,692
colorManipulator	0.00%	0.00%	3,904	3,904	1,543	1,543
docs.landing	0.00%	0.00%	51,531	51,531	11,368	11,368
docs.main	+0.01% 🔺	+0.01% 🔺	648,808	648,848	202,575	202,593
packages/material-ui/build/umd/material-ui.production.min.js	0.00%	0.00%	292,314	292,314	82,476	82,476

Generated by 🚫 dangerJS against 8572b1d

[kof]

I would recommend giving more time for a review next time.

LGTM

[oliviertassinari]

Thanks :), will do.