The life-changing magic of clang-tidying up

Summary:
Adding a `.clang-tidy` to a bunch of dirs under `react-native-github/ReactAndroid` and `react-native-github/ReactCommon`.

I don't want to add a single `.clang-tidy` at the root because we'll need more fine-grained control over what checks are enabled in different parts of the codebase; for example, fabric will and TM will probably have more checks enabled than older parts of the codebase that we're not actively modernizing, and the Hermes team probably wants its own config to be consistent with the rest of their codebase.

Starting off each `.clang-tidy` by only enabling clang-diagnostic; this is just to test that it's working. In the future, we'll work with the community to gradually enable more checks.

Changelog: [Internal]

Reviewed By: mdvacca

Differential Revision: D19705749

fbshipit-source-id: 979cea053b645ac4a9790340033bfcfb49ca0f97

ReactAndroid/src/main/java/com/facebook/hermes/.clang-tidy

@@ -0,0 +1,5 @@
+---
+Checks: '>
+clang-diagnostic-*,
+'
+...

ReactAndroid/src/main/java/com/facebook/react/fabric/.clang-tidy

@@ -0,0 +1,5 @@
+---
+Checks: '>
+clang-diagnostic-*,
+'
+...

ReactAndroid/src/main/java/com/facebook/react/modules/.clang-tidy

@@ -0,0 +1,5 @@
+---
+Checks: '>
+clang-diagnostic-*,
+'
+...

ReactAndroid/src/main/java/com/facebook/react/turbomodule/.clang-tidy

@@ -0,0 +1,5 @@
+---
+Checks: '>
+clang-diagnostic-*,
+'
+...