[REFACTOR] health 2.0: healthd_common -> libhealthloop

This change converts the original healthd_common.cpp to a
C++ class, HealthLoop, that manages the infinite loop in health-related
modules (charger, health HAL, healthd, etc.). By doing so, the global
static variables (including FDs and healthd_mode_ops) are cleaned up.

This helps us implement health HAL 2.1.

In order to support legacy modules (namely, healthd, charger, health HAL
2.0, which all depends on android.hardware.health@2.0-impl), a
healthd_common_adapter.cpp file is added to
android.hardware.health@2.0-impl, so that the following functions
in healthd/healthd.h continues to be implemented using the global
healthd_mode_ops:
    - healthd_register_event
    - healthd_battery_update_internal

Test: boot up the device and run VTS test on health HAL.
Bug: 137670450
Bug: 142260281
Change-Id: Iadcfc1315155404a3600f0e1219b5bc370d96409
diff --git a/health/utils/libhealthloop/utils.cpp b/health/utils/libhealthloop/utils.cpp
new file mode 100644
index 0000000..b0d153f
--- /dev/null
+++ b/health/utils/libhealthloop/utils.cpp
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <health/utils.h>
+namespace android {
+namespace hardware {
+namespace health {
+
+// Periodic chores fast interval in seconds
+#define DEFAULT_PERIODIC_CHORES_INTERVAL_FAST (60 * 1)
+// Periodic chores fast interval in seconds
+#define DEFAULT_PERIODIC_CHORES_INTERVAL_SLOW (60 * 10)
+
+void InitHealthdConfig(struct healthd_config* healthd_config) {
+    *healthd_config = {
+            .periodic_chores_interval_fast = DEFAULT_PERIODIC_CHORES_INTERVAL_FAST,
+            .periodic_chores_interval_slow = DEFAULT_PERIODIC_CHORES_INTERVAL_SLOW,
+            .batteryStatusPath = String8(String8::kEmptyString),
+            .batteryHealthPath = String8(String8::kEmptyString),
+            .batteryPresentPath = String8(String8::kEmptyString),
+            .batteryCapacityPath = String8(String8::kEmptyString),
+            .batteryVoltagePath = String8(String8::kEmptyString),
+            .batteryTemperaturePath = String8(String8::kEmptyString),
+            .batteryTechnologyPath = String8(String8::kEmptyString),
+            .batteryCurrentNowPath = String8(String8::kEmptyString),
+            .batteryCurrentAvgPath = String8(String8::kEmptyString),
+            .batteryChargeCounterPath = String8(String8::kEmptyString),
+            .batteryFullChargePath = String8(String8::kEmptyString),
+            .batteryCycleCountPath = String8(String8::kEmptyString),
+            .energyCounter = NULL,
+            .boot_min_cap = 0,
+            .screen_on = NULL,
+    };
+}
+
+}  // namespace health
+}  // namespace hardware
+}  // namespace android