Merge "health: drop backup instance for non-recovery."

namespace V2_0 {

sp<IHealth> get_health_service() {

    for (auto&& instanceName : {"default", "backup"}) {

    // For the core and vendor variant, the "backup" instance points to healthd,

    // which is removed.

    // For the recovery variant, the "backup" instance has a different

    // meaning. It points to android.hardware.health@2.0-impl-default.recovery

    // which was assumed by OEMs to be always installed when a

    // vendor-specific libhealthd is not necessary. Hence, its behavior

    // is kept. See health/2.0/README.md.

    // android.hardware.health@2.0-impl-default.recovery, and subsequently the

    // special handling of recovery mode below, can be removed once health@2.1

    // is the minimum required version (i.e. compatibility matrix level 5 is the

    // minimum supported level). Health 2.1 requires OEMs to install the

    // implementation to the recovery partition when it is necessary (i.e. on

    // non-A/B devices, where IsBatteryOk() is needed in recovery).

    for (auto&& instanceName :

#ifdef __ANDROID_RECOVERY__

         { "default", "backup" }

#else

         {"default"}

#endif

    ) {

        auto ret = IHealth::getService(instanceName);

        if (ret != nullptr) {

            return ret;