healthd: Add charger.recovery module.

This CL splits out healthd_mode_charger_nops for building
charger.recovery. It doesn't change the functionality of the charger
module under recovery, i.e. a) it still doesn't do much work other than
reporting the battery status periodically; b) it keeps calling
device-specific healthd functions (healthd_board_init and
healthd_board_battery_update) via the statically linked HAL.

Previously `charger -r` was used to indicate starting charger under
recovery mode. This CL makes it a noop since we've changed the caller in
recovery.

Bug: 73660730
Bug: 114042635
Test: Boot into charger mode on walleye. Check that charger UI works.
Test: Boot into recovery mode on walleye. Check that /system/bin/charger
      keeps working.
Test: Run charger_test on walleye.
Change-Id: Id91acfcc77ec315c2382392dc54e36c3e85de2eb
diff --git a/healthd/Android.bp b/healthd/Android.bp
index 6b00f81..2cf6be9 100644
--- a/healthd/Android.bp
+++ b/healthd/Android.bp
@@ -84,3 +84,29 @@
         "manifest_healthd.xml"
     ],
 }
+
+cc_library_static {
+    name: "libhealthd_charger_nops",
+
+    srcs: [
+        "healthd_mode_charger_nops.cpp",
+    ],
+
+    cflags: [
+        "-Wall",
+        "-Werror",
+    ],
+
+    header_libs: [
+        "libhealthd_headers",
+    ],
+
+    static_libs: [
+        "android.hardware.health@2.0-impl",
+    ],
+
+    shared_libs: [
+        "android.hardware.health@2.0",
+        "libutils",
+    ],
+}