Show the H+ icon in HSPA+ network

Adds the H+ icon. If status bar should distinguish HSPA data icon from
UMTS data icon, this icon is shown as default while connected to HSPA+
network.

Fixes: 69505790
Test: runtest systemui and visually check in demo mode
Change-Id: Ia911fcdb98d2c118e2ef71d7a062efbf72a0809c