Spencer Platt/Getty Images Google is taking a bite out of another piece of the health care pie. On Thursday, the tech giant announced plans to debut two wellness features that allow users of its Pixel smartphone to measure their heart and respiration rate using the device’s camera. Combined with Google’s other health bets, the rollout gives the tech giant a footprint in several major health markets — from wellness wearables to medical research — and tees it up to compete in a new way with rivals Apple and Amazon by making the Android smartphone a hub for health features.