Vivo has been teasing its upcoming X series flagship smartphones, the Vivo X300 Ultra and X300s, on Chinese social networking site Weibo. The company has already revealed the key details regarding the phone’s display, some camera sensors, and audio prowess. Now, a prominent gadget leaker, Digital Chat Station, has posted almost complete specs of the upcoming Vivo X300s. Vivo will pack the X300s with flagship-grade specs, including a 1.5K display According to the source, the Vivo X300s will feature a 6.78-inch BOE Q10+ screen bearing a resolution of 1.5K and a high refresh rate of 144Hz. Under the display, the…