bootstat: Remove custom uptime parser in favor of elapsedRealtime.

Refactored init/utils/boot_clock into base/chrono_utils.

Bug: 34352037
Test: none
Change-Id: Ied0c00867336b85922369d7ff37520e3d28fc61e
diff --git a/base/Android.bp b/base/Android.bp
index b9a6e0b..515b063 100644
--- a/base/Android.bp
+++ b/base/Android.bp
@@ -42,21 +42,31 @@
             srcs: [
                 "errors_unix.cpp",
                 "properties.cpp",
+                "chrono_utils.cpp",
             ],
             cppflags: ["-Wexit-time-destructors"],
         },
         darwin: {
-            srcs: ["errors_unix.cpp"],
+            srcs: [
+                "errors_unix.cpp",
+            ],
             cppflags: ["-Wexit-time-destructors"],
         },
         linux_bionic: {
-            srcs: ["errors_unix.cpp"],
+            srcs: [
+                "chrono_utils.cpp",
+                "errors_unix.cpp",
+            ],
             cppflags: ["-Wexit-time-destructors"],
             enabled: true,
         },
         linux: {
-            srcs: ["errors_unix.cpp"],
+            srcs: [
+                "chrono_utils.cpp",
+                "errors_unix.cpp",
+            ],
             cppflags: ["-Wexit-time-destructors"],
+            host_ldlibs: ["-lrt"],
         },
         windows: {
             srcs: [
@@ -88,7 +98,14 @@
     ],
     target: {
         android: {
-            srcs: ["properties_test.cpp"],
+            srcs: [
+                "chrono_utils_test.cpp",
+                "properties_test.cpp"
+            ],
+        },
+        linux: {
+            srcs: ["chrono_utils_test.cpp"],
+            host_ldlibs: ["-lrt"],
         },
         windows: {
             srcs: ["utf8_test.cpp"],