Enable -Wshadow for input code

To avoid common programming mistakes, enable -Wshadow for input code.
This requires several refactors, such as using range-based for loops and
avoiding repeating variable names that are already in scope.

To allow for -Wshadow, we convert to unordered_map and use a range-based
loop.

Bug: 142017994
Test: atest libinput_tests inputflinger_tests
Change-Id: Icb65045d3322eccc312bca63287e38897d9f9ff6
diff --git a/services/inputflinger/reader/EventHub.cpp b/services/inputflinger/reader/EventHub.cpp
index a1514af..18fcaed 100644
--- a/services/inputflinger/reader/EventHub.cpp
+++ b/services/inputflinger/reader/EventHub.cpp
@@ -933,11 +933,11 @@
                 if (eventItem.events & EPOLLIN) {
                     ALOGV("awoken after wake()");
                     awoken = true;
-                    char buffer[16];
+                    char wakeReadBuffer[16];
                     ssize_t nRead;
                     do {
-                        nRead = read(mWakeReadPipeFd, buffer, sizeof(buffer));
-                    } while ((nRead == -1 && errno == EINTR) || nRead == sizeof(buffer));
+                        nRead = read(mWakeReadPipeFd, wakeReadBuffer, sizeof(wakeReadBuffer));
+                    } while ((nRead == -1 && errno == EINTR) || nRead == sizeof(wakeReadBuffer));
                 } else {
                     ALOGW("Received unexpected epoll event 0x%08x for wake read pipe.",
                           eventItem.events);